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111-764: The American Legion Memorial Bridge, also known as the American Legion Bridge and formerly as the Cabin John Bridge, is a bridge carrying Interstate 495 (Capital Beltway) across the Potomac River between Montgomery County , Maryland and Fairfax County , Virginia in the United States. It is an American Water Landmark . Plummers Island is located immediately downstream of the bridge. The bridge has five traffic lanes in each direction. The outermost lane in each direction

222-600: A bridge-restaurant which is a bridge built to serve as a restaurant. Other suspension bridge towers carry transmission antennas. Conservationists use wildlife overpasses to reduce habitat fragmentation and animal-vehicle collisions. The first animal bridges sprung up in France in the 1950s, and these types of bridges are now used worldwide to protect both large and small wildlife. Bridges are subject to unplanned uses as well. The areas underneath some bridges have become makeshift shelters and homes to homeless people, and

333-407: A rent-seeking behavior, which leads to spiraling costs for users and/or taxpayers in the operation phase of the project. Some public–private partnerships, when the development of new technologies is involved, include profit-sharing agreements. This generally involves splitting revenues between the inventor and the public once a technology is commercialized. Profit-sharing agreements may stand over

444-525: A bridge is to be designed, standards authorities specify simplified notional load models, notably HL-93, intended to give the same load effects as the characteristic maximum values. The Eurocode is an example of a standard for bridge traffic loading that was developed in this way. Most bridge standards are only applicable for short and medium spans - for example, the Eurocode is only applicable for loaded lengths up to 200 m. Longer spans are dealt with on

555-470: A building contractor, a maintenance company, and one or more equity investors. The two former are typically equity holders in the project, who make decisions but are only repaid when the debts are paid, while the latter is the project's creditor (debt holder). It is the SPV that signs the contract with the government and with subcontractors to build the facility and then maintain it. A typical PPP example would be

666-471: A case-by-case basis. It is generally accepted that the intensity of load reduces as span increases because the probability of many trucks being closely spaced and extremely heavy reduces as the number of trucks involved increases. It is also generally assumed that short spans are governed by a small number of trucks traveling at high speed, with an allowance for dynamics. Longer spans on the other hand, are governed by congested traffic and no allowance for dynamics

777-480: A combination of structural health monitoring and testing. This is regulated in country-specific engineer standards and includes an ongoing monitoring every three to six months, a simple test or inspection every two to three years and a major inspection every six to ten years. In Europe, the cost of maintenance is considerable and is higher in some countries than spending on new bridges. The lifetime of welded steel bridges can be significantly extended by aftertreatment of

888-399: A different site, and re-used. They are important in military engineering and are also used to carry traffic while an old bridge is being rebuilt. Movable bridges are designed to move out of the way of boats or other kinds of traffic, which would otherwise be too tall to fit. These are generally electrically powered. The Tank bridge transporter (TBT) has the same cross-country performance as

999-503: A federal grant to support rebuilding of the bridge and expand a portion of I-495 leading to the junction with I-270. Bridge A bridge is a structure built to span a physical obstacle (such as a body of water , valley , road, or railway) without blocking the path underneath. It is constructed for the purpose of providing passage over the obstacle, which is usually something that is otherwise difficult or impossible to cross. There are many different designs of bridges, each serving

1110-543: A few will predominate. The separation of forces and moments may be quite clear. In a suspension or cable-stayed bridge , the elements in tension are distinct in shape and placement. In other cases the forces may be distributed among a large number of members, as in a truss. The world's longest beam bridge is Lake Pontchartrain Causeway in southern Louisiana in the United States, at 23.83 miles (38.35 km), with individual spans of 56 feet (17 m). Beam bridges are

1221-475: A fixed period of time or in perpetuity. Using PPPs have been justified in various ways over time. Advocates generally argue that PPPs enable the public sector to harness the expertise and efficiencies that the private sector can bring to the delivery of certain facilities and services traditionally procured and delivered by the public sector. On the other hand, critics suggest that PPPs are part of an ideological program that seeks to privatize public services for

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1332-450: A hospital building financed and constructed by a private developer and then leased to the hospital authority. The private developer then acts as landlord, providing housekeeping and other non-medical services, while the hospital itself provides medical services. The SPV links the firms responsible of the building phase and the operating phase together. Hence there is a strong incentives in the building stage to make investments with regard to

1443-407: A mix of public and private endeavors throughout history. Muhammad Ali of Egypt utilized " concessions " in the early 1800s to obtain public works for minimal cost while the concessionaires' companies made most of the profits from projects such as railroads and dams. Much of the early infrastructure of the United States was built by what can be considered public–private partnerships. This includes

1554-463: A particular purpose and applicable to different situations. Designs of bridges vary depending on factors such as the function of the bridge, the nature of the terrain where the bridge is constructed and anchored, the material used to make it, and the funds available to build it. The earliest bridges were likely made with fallen trees and stepping stones . The Neolithic people built boardwalk bridges across marshland. The Arkadiko Bridge , dating from

1665-421: A private or nonprofit entity." A more general term for such agreements is "shared service delivery", in which public-sector entities join with private firms or non-profit organizations to provide services to citizens. There is a semantic debate pertaining to whether public–private partnerships constitute privatization or not. Some argue that it isn't "privatization" because the government retains ownership of

1776-492: A project cheaper for taxpayers. This can be done by cutting corners, designing the project so as to be more profitable in the operational phase, charging user fees, and/or monetizing aspects of the projects not covered by the contract. For P3 schools in Nova Scotia , this latter aspect has included restricting the use of schools' fields and interior walls, and charging after-hours facility access to community groups at 10 times

1887-455: A radical reform of government service provision. In 1997, the new British government of Tony Blair 's Labour Party expanded the PFI but sought to shift the emphasis to the achievement of "value for money", mainly through an appropriate allocation of risk. Blair created Partnerships UK (PUK), a new semi-independent organization to replace the previous pro-PPP government institutions. Its mandate

1998-605: A range of costs, the exact nature of which has changed over time and varies by jurisdiction. One thing that does remain consistent, however, is the favoring of "risk transfer" to the private partner, to the detriment of the public sector comparator. Value for money assessment procedures were incorporated into the PFI and its Australian and Canadian counterparts beginning in the late 1990s and early 2000s. A 2012 study showed that value-for-money frameworks were still inadequate as an effective method of evaluating PPP proposals. The problem

2109-561: A simple type of suspension bridge , were used by the Inca civilization in the Andes mountains of South America, just prior to European colonization in the 16th century. The Ashanti built bridges over streams and rivers . They were constructed by pounding four large forked tree trunks into the stream bed, placing beams along these forked pillars, then positioning cross-beams that were finally covered with four to six inches of dirt. During

2220-593: A span of 552 m (1,811 ft). The bridge was opened 29 April 2009, in Chongqing , China. The longest suspension bridge in the world is the 4,608 m (15,118 ft) 1915 Çanakkale Bridge in Turkey. The longest cable-stayed bridge since 2012 is the 1,104 m (3,622 ft) Russky Bridge in Vladivostok , Russia. Some Engineers sub-divide 'beam' bridges into slab, beam-and-slab and box girder on

2331-749: A stream. Often in palaces, a bridge will be built over an artificial waterway as symbolic of a passage to an important place or state of mind. A set of five bridges cross a sinuous waterway in an important courtyard of the Forbidden City in Beijing, China. The central bridge was reserved exclusively for the use of the Emperor and Empress, with their attendants. The estimated life of bridges varies between 25 and 80 years depending on location and material. Bridges may age hundred years with proper maintenance and rehabilitation. Bridge maintenance consisting of

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2442-489: A tank even when fully loaded. It can deploy, drop off and load bridges independently, but it cannot recover them. Double-decked (or double-decker) bridges have two levels, such as the George Washington Bridge , connecting New York City to Bergen County , New Jersey , US, as the world's busiest bridge, carrying 102 million vehicles annually; truss work between the roadway levels provided stiffness to

2553-458: A transfer of risk, but when things go wrong the risk stays with the public sector and, at the end of the day, the public because the companies expect to get paid. The health board should now be seeking an exit from this failed arrangement with Consort and at the very least be looking to bring facilities management back in-house. Furthermore, assessments ignore the practices of risk transfers to contractors under traditional procurement methods. As for

2664-454: A vested interest in recommending the PPP option over the traditional public procurement method. The lack of transparency surrounding individual PPP projects makes it difficult to draft independent value-for-money assessments. A number of Australian studies of early initiatives to promote private investment in infrastructure concluded that in most cases, the schemes being proposed were inferior to

2775-763: A western bridge around the Loudoun County / Fairfax County line in Virginia ( Virginia Route 28 / Fairfax County Parkway area), or farther out as part of the Western Transportation Corridor. Opponents claim that another bridge would increase development in those areas, increase traffic, and generate more pollution in the Chesapeake Bay . The bridge crosses the western terminus of the Potomac Heritage Trail and

2886-496: A wide range of risk allocations, funding arrangements, and transparency requirements. The advancement of PPPs, as a concept and a practice, is a product of the new public management of the late 20th century, the rise of neoliberalism, and globalization pressures. Despite there being no formal consensus regarding a definition, the term has been defined by major entities. For example, The OECD formally defines public–private partnerships as "long term contractual arrangements between

2997-462: Is a bridge that carries water, resembling a viaduct, which is a bridge that connects points of equal height. A road-rail bridge carries both road and rail traffic. Overway is a term for a bridge that separates incompatible intersecting traffic, especially road and rail. Some bridges accommodate other purposes, such as the tower of Nový Most Bridge in Bratislava , which features a restaurant, or

3108-588: Is an early example of a double-decked bridge. The upper level carries a railway, and the lower level is used for road traffic. Other examples include Britannia Bridge over the Menai Strait and Craigavon Bridge in Derry, Northern Ireland. The Oresund Bridge between Copenhagen and Malmö consists of a four-lane highway on the upper level and a pair of railway tracks at the lower level. Tower Bridge in London

3219-742: Is an entrance/exit-only lane for traffic to/from the Clara Barton Parkway in Maryland and the George Washington Memorial Parkway and Georgetown Pike ( State Route 193 ) in Virginia. There are no facilities for pedestrians or cyclists, which are prohibited. Opened on December 31, 1962, the bridge was originally named the "Cabin John Bridge" because of its proximity to the community of Cabin John on

3330-506: Is borne exclusively by the users of the service, for example, by toll road users such as in the case of Toronto 's Yonge Street at the dawn of the 19th century, and the more recent Highway 407 in Ontario . In other types (notably the PFI), capital investment is made by the private sector on the basis of a contract with the government to provide agreed-on services, and the cost of providing

3441-496: Is different example of a double-decked bridge, with the central section consisting of a low-level bascule span and a high-level footbridge . A viaduct is made up of multiple bridges connected into one longer structure. The longest and some of the highest bridges are viaducts, such as the Lake Pontchartrain Causeway and Millau Viaduct . A multi-way bridge has three or more separate spans which meet near

American Legion Memorial Bridge (Potomac River) - Misplaced Pages Continue

3552-484: Is established or renewed, the financing is, from the public sector's perspective, "on-balance sheet". According to PPP advocates, the public sector will regularly benefit from significantly deferred cash flows. This viewpoint has been contested through research that shows that a majority of PPP projects ultimately cost significantly more than traditional public ones. In the European Union, the fact that PPP debt

3663-417: Is led by architects, bridges are usually designed by engineers. This follows from the importance of the engineering requirements; namely spanning the obstacle and having the durability to survive, with minimal maintenance, in an aggressive outdoor environment. Bridges are first analysed; the bending moment and shear force distributions are calculated due to the applied loads. For this, the finite element method

3774-540: Is needed. Calculating the loading due to congested traffic remains a challenge as there is a paucity of data on inter-vehicle gaps, both within-lane and inter-lane, in congested conditions. Weigh-in-Motion (WIM) systems provide data on inter-vehicle gaps but only operate well in free flowing traffic conditions. Some authors have used cameras to measure gaps and vehicle lengths in jammed situations and have inferred weights from lengths using WIM data. Others have used microsimulation to generate typical clusters of vehicles on

3885-479: Is not recorded as debt and remains largely "off-balance-sheet" has become a major concern. Indeed, keeping the PPP project and its contingent liabilities "off balance sheet" means that the true cost of the project is hidden. According to the International Monetary Fund , economic ownership of the asset should determine whether to record PPP-related assets and liabilities in the government's or

3996-462: Is responsible, and the Private sector assumes that risk at a cost for the taxpayer. If the value of the risk transfer is appraised too high, then the government is overpaying for P3 projects. Incidentally, a 2018 UK Parliament report underlines that some private investors have made large returns from PPP deals, suggesting that departments are overpaying for transferring the risks of projects to

4107-480: Is that it is unclear what the catchy term "value-for-money" means in the technical details relating to their practical implementation. A Scottish auditor once qualified this use of the term as "technocratic mumbo-jumbo". Project promoters often contract a PPP unit or one of the Big Four accounting firms to conduct the value for money assessments. Because these firms also offer PPP consultancy services, they have

4218-454: Is that most of the up-front financing is made through the private sector. The way this financing is done differs significantly by country. For P3s in the UK, bonds are used rather than bank loans . In Canada, P3 projects usually use loans that must be repaid within five years, and the projects are refinanced at a later date. In some types of public–private partnership, the cost of using the service

4329-737: Is the most popular. The analysis can be one-, two-, or three-dimensional. For the majority of bridges, a two-dimensional plate model (often with stiffening beams) is sufficient or an upstand finite element model. On completion of the analysis, the bridge is designed to resist the applied bending moments and shear forces, section sizes are selected with sufficient capacity to resist the stresses. Many bridges are made of prestressed concrete which has good durability properties, either by pre-tensioning of beams prior to installation or post-tensioning on site. In most countries, bridges, like other structures, are designed according to Load and Resistance Factor Design (LRFD) principles. In simple terms, this means that

4440-674: The City of London , accountancy and consultancy firms who had a vested interest in the success of PFI. Around the same time, PPPs were being initiated haphazardly in various OECD countries. The first governments to implement them were ideologically neoliberal and short on revenues : they were thus politically and fiscally inclined to try out alternative forms of public procurement. These early PPP projects were usually pitched by wealthy and politically connected business magnates . This explains why each countries experimenting with PPPs started in different sectors . At that time, PPPs were seen as

4551-647: The George Washington Memorial Parkway on the Virginian side of the Potomac River. On the Maryland side, the bridge crosses over MacArthur Boulevard , the Clara Barton Parkway and the Chesapeake and Ohio Canal . Lock 13 (Seven Locks 6) of the canal is underneath the bridge. The American Legion Memorial Bridge is one of the two locations at which the Capital Beltway crosses the Potomac River;

American Legion Memorial Bridge (Potomac River) - Misplaced Pages Continue

4662-642: The Hellenistic era can be found in the Peloponnese. The greatest bridge builders of antiquity were the ancient Romans . The Romans built arch bridges and aqueducts that could stand in conditions that would damage or destroy earlier designs, some of which still stand today. An example is the Alcántara Bridge , built over the river Tagus , in Spain. The Romans also used cement, which reduced

4773-495: The Maryland Department of Transportation (MDOT) released its more than 18,000-page Draft Environmental Impact Statement (DEIS) on the project, which addresses the construction project's impacts on people and the environment. The expansion project would destroy large parts of Plummers Island , which is located immediately downstream of the bridge. It would destroy or require relocation of the channel that separates

4884-864: The University of Minnesota ). Likewise, in Toronto , the Prince Edward Viaduct has five lanes of motor traffic, bicycle lanes, and sidewalks on its upper deck; and a pair of tracks for the Bloor–Danforth subway line on its lower deck. The western span of the San Francisco–Oakland Bay Bridge also has two levels. Robert Stephenson 's High Level Bridge across the River Tyne in Newcastle upon Tyne , completed in 1849,

4995-548: The public-sector borrowing requirement , although, as already noted, the effect on public accounts was largely illusory. Initially, the private sector was unenthusiastic about PFI, and the public sector was opposed to its implementation. In 1993, the Chancellor of the Exchequer described its progress as "disappointingly slow". To help promote and implement the policy, Major created institutions staffed with people linked with

5106-504: The river Severn . With the Industrial Revolution in the 19th century, truss systems of wrought iron were developed for larger bridges, but iron does not have the tensile strength to support large loads. With the advent of steel, which has a high tensile strength, much larger bridges were built, many using the ideas of Gustave Eiffel . In Canada and the United States, numerous timber covered bridges were built in

5217-527: The 13th century BC, in the Peloponnese is one of the oldest arch bridges in existence and use. The Oxford English Dictionary traces the origin of the word bridge to an Old English word brycg , of the same meaning.   The Oxford English Dictionary also notes that there is some suggestion that the word can be traced directly back to Proto-Indo-European *bʰrēw-. However, they also note that "this poses semantic problems." The origin of

5328-523: The 18th century, there were many innovations in the design of timber bridges by Hans Ulrich Grubenmann , Johannes Grubenmann , as well as others. The first book on bridge engineering was written by Hubert Gautier in 1716. A major breakthrough in bridge technology came with the erection of the Iron Bridge in Shropshire, England in 1779. It used cast iron for the first time as arches to cross

5439-773: The Maryland side of the Potomac River. The bridge opened without a ceremony due to the cold weather. On May 30, 1969, the bridge was officially renamed the "American Legion Memorial Bridge" in a ceremony led by Lt. Gen. Lewis B. Hershey , director of the U.S. Selective Service System . This action reduced confusion with the Union Arch Bridge , which carries the Washington Aqueduct and MacArthur Boulevard across Cabin John Creek and which some people also called "the Cabin John Bridge". The bridge

5550-634: The Philadelphia and Lancaster Turnpike road in Pennsylvania, which was initiated in 1792, an early steamboat line between New York and New Jersey in 1808; many of the railroads, including the nation's first railroad , chartered in New Jersey in 1815; and most of the modern electric grid . In Newfoundland, Robert Gillespie Reid contracted to operate the railways for fifty years from 1898, though originally they were to become his property at

5661-624: The appearance of the bridge can have great importance. Often, this is the case with a large bridge that serves as an entrance to a city, or crosses over a main harbor entrance. These are sometimes known as signature bridges. Designers of bridges in parks and along parkways often place more importance on aesthetics, as well. Examples include the stone-faced bridges along the Taconic State Parkway in New York. Bridges are typically more aesthetically pleasing if they are simple in shape,

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5772-453: The assessment of PPPs which focused heavily on value for money . Heather Whiteside defines P3 "Value for money" as: Not to be confused with lower overall project costs, value for money is a concept used to evaluate P3 private-partner bids against a hypothetical public sector comparator designed to approximate the costs of a fully public option (in terms of design, construction, financing, and operations). P3 value for money calculations consider

5883-643: The attention of the general public in the 1990s by the novel, movie and play The Bridges of Madison County . In 1927, welding pioneer Stefan Bryła designed the first welded road bridge in the world, the Maurzyce Bridge which was later built across the river Słudwia at Maurzyce near Łowicz , Poland in 1929. In 1995, the American Welding Society presented the Historic Welded Structure Award for

5994-583: The basis of ideology and accounting fallacies arising from the fact that public accounts did not distinguish between recurrent and capital expenditures. In 1992, the Conservative government of John Major in the United Kingdom introduced the Private finance initiative (PFI), the first systematic program aimed at encouraging public–private partnerships. The 1992 program focused on reducing

6105-596: The basis of their cross-section. A slab can be solid or voided (though this is no longer favored for inspectability reasons) while beam-and-slab consists of concrete or steel girders connected by a concrete slab. A box-girder cross-section consists of a single-cell or multi-cellular box. In recent years, integral bridge construction has also become popular. Most bridges are fixed bridges, meaning they have no moving parts and stay in one place until they fail or are demolished. Temporary bridges, such as Bailey bridges , are designed to be assembled, taken apart, transported to

6216-414: The bill for disproportionately high interest costs. PPPs also have high transaction costs . PPPs are controversial as funding tools, largely over concerns that public return on investment is lower than returns for the private funder. PPPs are closely related to concepts such as privatization and the contracting out of government services. The secrecy surrounding their financial details complexifies

6327-437: The bridge to Poland. Bridges can be categorized in several different ways. Common categories include the type of structural elements used, by what they carry, whether they are fixed or movable, and by the materials used. Bridges may be classified by how the actions of tension , compression , bending , torsion and shear are distributed through their structure. Most bridges will employ all of these to some degree, but only

6438-472: The bridge. Public%E2%80%93private partnership Cooperation between private actors, corporations and governments has existed since the inception of sovereign states , notably for the purpose of tax collection and colonization . Contemporary "public–private partnerships" came into being around the end of the 20th century. They were aimed at increasing the private sector's involvement in public administration . They were seen by governments around

6549-439: The center of the bridge. Multi-way bridges with only three spans appear as a "T" or "Y" when viewed from above. Multi-way bridges are extremely rare. The Tridge , Margaret Bridge , and Zanesville Y-Bridge are examples. A bridge can be categorized by what it is designed to carry, such as trains, pedestrian or road traffic ( road bridge ), a pipeline ( Pipe bridge ) or waterway for water transport or barge traffic. An aqueduct

6660-496: The contractor. One of the main criticisms of public–private partnerships is the lack of accountability and transparency associated with these projects. Part of the reason why evidence of PPP performance is often unavailable is that most financial details of P3s are under the veil of commercial confidentiality provisions, and unavailable to researchers and the public. Around the world, opponents of P3s have launched judicial procedures to access greater P3 project documentation than

6771-727: The contractual complexities and rigidities they entail". In the United Kingdom, many private finance initiative programs ran dramatically over budget and have not provided value for money for the taxpayer, with some projects costing more to cancel than to complete. An in-depth study conducted by the National Audit Office of the United Kingdom concluded that the private finance initiative model had proved to be more expensive and less efficient in supporting hospitals, schools, and other public infrastructure than public financing. A treasury select committee stated that 'PFI

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6882-413: The cost of the complex scientific laboratory, which was ultimately built, was very much larger than estimated. On the other hand, Allyson Pollock argues that in many PFI projects risks are not in fact transferred to the private sector and, based on the research findings of Pollock and others, George Monbiot argues that the calculation of risk in PFI projects is highly subjective, and is skewed to favor

6993-465: The costs to be larger than what was projected. Another risk within this area is with change of governance from differing political representatives could lead to projects being diminished or reduction of the allocated budget. This is common within PPPs as different political actors are likely to scrutinise their opponents based on their ideological positions. Private monopolies created by PPPs can generate

7104-467: The deck is thinner in proportion to its span, the lines of the structure are continuous, and the shapes of the structural elements reflect the forces acting on them. To create a beautiful image, some bridges are built much taller than necessary. This type, often found in east-Asian style gardens, is called a Moon bridge , evoking a rising full moon. Other garden bridges may cross only a dry bed of stream-washed pebbles, intended only to convey an impression of

7215-478: The end of the period. The late 20th and early 21st century saw a clear trend toward governments across the globe making greater use of various PPP arrangements. Pressure to change the model of public procurement was associated with the neoliberal turn. Instigators of the policy portrayed PPPs as a solution to concerns about the growing level of public debt during the 1970s and 1980s. They sought to encourage private investment in infrastructure , initially on

7326-602: The facility and/or remains responsible for public service delivery. Others argue that they exist on a continuum of privatization, P3s being a more limited form of privatization than the outright sale of public assets, but more extensive than simply contracting out government services. Because "privatization" has a negative connotation in some circles, supporters of P3s generally take the position that P3s do not constitute privatization, while P3 opponents argue that they do. The Canadian Union of Public Employees describes P3s as "privatization by stealth". Governments have used such

7437-618: The first human-made bridges with significant span were probably intentionally felled trees. Among the oldest timber bridges is the Holzbrücke Rapperswil-Hurden bridge that crossed upper Lake Zürich in Switzerland; prehistoric timber pilings discovered to the west of the Seedamm causeway date back to 1523 BC. The first wooden footbridge there led across Lake Zürich; it was reconstructed several times through

7548-407: The government and a private partner whereby the latter delivers and funds public services using a capital asset, sharing the associated risks". According to David L. Weimer and Aidan R. Vining, "A P3 typically involves a private entity financing, constructing, or managing a project in return for a promised stream of payments directly from government or indirectly from users over the projected life of

7659-410: The government of the day appear more fiscally responsible , while offloading the costs of their projects to service users or future governments. In Canada, many auditors general have condemned this practice, and forced governments to include PPP projects "on-balance sheet". On PPP projects where the public sector intends to compensate the private sector through availability payments once the facility

7770-502: The idea that the private sector is inherently better at managing risk, there has been no comprehensive study comparing risk management by the public sector and by P3s. Auditor Generals of Quebec , Ontario and New Brunswick have publicly questioned P3 rationales based on a transfer of risk, the latter stating he was "unable to develop any substantive evidence supporting risk transfer decisions". Furthermore, many PPP concessions proved to be unstable and required to be renegotiated to favor

7881-546: The island from the mainland, clear-cut trees, and level a significant portion of the island. The native beech forest on the mainland side would also have to be cut down; wetlands between the mainland and the island would be destroyed, which can lead to a heavy infestation with invasive plants. In August 2022 the Federal Highway Administration approved the proposed project. In October 2022 environmental and historic preservation groups filed suit against

7992-473: The lack of investor rights guarantees, commercial confidentiality laws, and dedicated state spending on public infrastructure in these countries made the implementation of public–private partnership in transition economies difficult. PPPs in the countries usually can't rely on stable revenues from user fees either. The World Bank 's Public-Private Infrastructure Advisory Forum attempts to mitigate these challenges. A defining aspect of many infrastructure P3s

8103-781: The late 1700s to the late 1800s, reminiscent of earlier designs in Germany and Switzerland. Some covered bridges were also built in Asia. In later years, some were partly made of stone or metal but the trusses were usually still made of wood; in the United States, there were three styles of trusses, the Queen Post, the Burr Arch and the Town Lattice. Hundreds of these structures still stand in North America. They were brought to

8214-470: The late 2nd century AD, when the Roman Empire built a 6-metre-wide (20 ft) wooden bridge to carry transport across the lake. Between 1358 and 1360, Rudolf IV, Duke of Austria , built a 'new' wooden bridge across the lake that was used until 1878; it was approximately 1,450 metres (4,760 ft) long and 4 metres (13 ft) wide. On 6 April 2001, a reconstruction of the original wooden footbridge

8325-419: The limited "bottom line" sheets available on the project's websites. When they are successful, the documents they receive are often heavily redacted. A 2007 survey of U.S. city managers revealed that communities often fail to sufficiently monitor PPPs: "For instance, in 2002, only 47.3% of managers involved with private firms as delivery partners reported that they evaluate that service delivery. By 2007, that

8436-427: The load is factored up by a factor greater than unity, while the resistance or capacity of the structure is factored down, by a factor less than unity. The effect of the factored load (stress, bending moment) should be less than the factored resistance to that effect. Both of these factors allow for uncertainty and are greater when the uncertainty is greater. Most bridges are utilitarian in appearance, but in some cases,

8547-480: The majority of P3 projects in Australia. Wall Street firms have increased their interest in PPP since the 2008 financial crisis. Government sometimes make in kind contributions to a PPP, notably with the transfer of existing assets. In projects that are aimed at creating public goods , like in the infrastructure sector, the government may provide a capital subsidy in the form of a one-time grant so as to make

8658-741: The most populous counties in their respective states. It is also the only major crossing between Maryland and Virginia between the Point of Rocks Bridge , more than 30 miles (50 km) upstream and the Chain Bridge downstream between the Commonwealth of Virginia and the District of Columbia . Congestion on the American Legion Bridge and commuter travel between the western Washington suburbs in both states has fueled support for

8769-737: The operating stage. These investments can be desirable but may also be undesirable (e.g., when the investments not only reduce operating costs but also reduce service quality). Public infrastructure is a relatively low-risk, high-reward investment, and combining it with complex arrangements and contracts that guarantee and secure the cash flows make PPP projects prime candidates for project financing . The equity investors in SPVs are usually institutional investors such as pension funds, life insurance companies, sovereign wealth and superannuation funds, and banks. Major P3 investors include AustralianSuper , OMERS and Dutch state-owned bank ABN AMRO , which funded

8880-553: The other is the Woodrow Wilson Memorial Bridge . In September 2017, Maryland Governor Larry Hogan announced plans to widen interstate highways I-270 and I-495 (Capital Beltway) with toll-funded express lanes planned, built, and operated through a public–private partnership (P3). It was announced on November 12, 2019, that the existing spans will be rebuilt and replaced with a new structure expanding capacity from eight to twelve lanes. On July 10, 2020,

8991-629: The past, these load models were agreed by standard drafting committees of experts but today, this situation is changing. It is now possible to measure the components of bridge traffic load, to weigh trucks, using weigh-in-motion (WIM) technologies. With extensive WIM databases, it is possible to calculate the maximum expected load effect in the specified return period. This is an active area of research, addressing issues of opposing direction lanes, side-by-side (same direction) lanes, traffic growth, permit/non-permit vehicles and long-span bridges (see below). Rather than repeat this complex process every time

9102-472: The principles of Load and Resistance Factor Design . Before factoring to allow for uncertainty, the load effect is generally considered to be the maximum characteristic value in a specified return period . Notably, in Europe, it is the maximum value expected in 1000 years. Bridge standards generally include a load model, deemed to represent the characteristic maximum load to be expected in the return period. In

9213-418: The private corporation's balance sheet is not straightforward. The effectiveness of PPPs as cost-saving venture has been refuted by numerous studies. Research has showed that on average, governments pay more for PPPs projects than for traditional publicly financed projects. The higher cost of P3s is attributed to these systemic factors: Sometimes, private partners manage to overcome these costs and provide

9324-610: The private sector, one of the Treasury's stated benefits of PPP. Supporters of P3s claim that risk is successfully transferred from public to private sectors as a result of P3, and that the private sector is better at risk management . As an example of successful risk transfer, they cite the case of the National Physical Laboratory . This deal ultimately caused the collapse of the building contractor Laser (a joint venture between Serco and John Laing ) when

9435-481: The private sector: When private companies take on a PFI project, they are deemed to acquire risks the state would otherwise have carried. These risks carry a price, which proves to be remarkably responsive to the outcome you want. A paper in the British Medical Journal shows that before risk was costed, the hospital schemes it studied would have been built much more cheaply with public funds. After

9546-460: The process of evaluating whether PPPs have been successful. PPP advocates highlight the sharing of risk and the development of innovation , while critics decry their higher costs and issues of accountability . Evidence of PPP performance in terms of value for money and efficiency, for example, is mixed and often unavailable. There is no consensus about how to define a PPP. The term can cover hundreds of different types of long-term contracts with

9657-403: The profits of private entities. PPPs are often structured so that borrowing for the project does not appear on the balance sheet of the public-sector body seeking to make a capital investment. Rather, the borrowing is incurred by the private-sector vehicle implementing the project, with or without an explicit backup guarantee of the loan by the public body. On PPP projects where the cost of using

9768-473: The project economically viable. In other cases, the government may support the project by providing revenue subsidies, including tax breaks or by guaranteed annual revenues for a fixed period. Within public-private partnerships (PPPs), there are various risks associated. One risk common within PPPs is the lack of proper or accurate cost evaluation. Oftentimes the estimated costs of a project will not properly account for delays or unexpected events, leading to

9879-475: The project or some other specified period of time". A 2013 study published in State and Local Government Review found that definitions of public-private partnerships vary widely between municipalities: "Many public and private officials tout public–private partnerships for any number of activities, when in truth the relationship is contractual, a franchise, or the load shedding of some previously public service to

9990-483: The rate of non-P3 schools. In Ontario, a 2012 review of 28 projects showed that the costs were on average 16% lower for traditional publicly procured projects than for PPPs. A 2014 report by the Auditor General of Ontario said that the province overpaid by $ 8 billion through PPPs. In response to these negative findings about the costs and quality of P3 projects, proponents developed formal procedures for

10101-494: The risk was costed, they all tipped the other way; in several cases by less than 0.1%. Following an incident in the Royal Infirmary of Edinburgh where surgeons were forced to continue a heart operation in the dark following a power cut caused by PFI operating company Consort, Dave Watson from Unison criticized the way the PFI contract operates: It's a costly and inefficient way of delivering services. It's meant to mean

10212-763: The roadways and reduced movement of the upper level when the lower level was installed three decades after the upper level. The Tsing Ma Bridge and Kap Shui Mun Bridge in Hong Kong have six lanes on their upper decks, and on their lower decks there are two lanes and a pair of tracks for MTR metro trains. Some double-decked bridges only use one level for street traffic; the Washington Avenue Bridge in Minneapolis reserves its lower level for automobile and light rail traffic and its upper level for pedestrian and bicycle traffic (predominantly students at

10323-734: The same year, has the span of 90 m (295 ft) and crosses the valley of the Syrabach River. The difference between the two is that the Solkan Bridge was built from stone blocks, whereas the Friedensbrücke was built from a mixture of crushed stone and cement mortar. The world's largest arch bridge is the Chaotianmen Bridge over the Yangtze River with a length of 1,741 m (5,712 ft) and

10434-441: The service is intended to be borne exclusively by the end-user, or through a lease billed to the government every year during the operation phase of the project, the PPP is, from the public sector's perspective, an " off-balance sheet " method of financing the delivery of new or refurbished public-sector assets. This justification was particularly important during the 1990s, but has been exposed as an accounting trick designed to make

10545-414: The services is borne wholly or in part by the government. Typically, a private-sector consortium forms a special company called a special-purpose vehicle (SPV) to develop, build, maintain, and operate the asset for the contracted period. In cases where the government has invested in the project, it is typically (but not always) allotted an equity share in the SPV. The consortium is usually made up of

10656-653: The simplest and oldest type of bridge in use today, and are a popular type. Some cantilever bridges also have a smaller beam connecting the two cantilevers, for extra strength. The largest cantilever bridge is the 549-metre (1,801 ft) Quebec Bridge in Quebec, Canada. With the span of 220 metres (720 ft), the Solkan Bridge over the Soča River at Solkan in Slovenia is the second-largest stone bridge in

10767-556: The standard model of public procurement based on competitively tendered construction of publicly owned assets. In 2009, the New Zealand Treasury , in response to inquiries by the new National Party government, released a report on PPP schemes that concluded that "there is little reliable empirical evidence about the costs and benefits of PPPs" and that there "are other ways of obtaining private sector finance", as well as that "the advantages of PPPs must be weighed against

10878-583: The state, citing deficiencies in the environmental review process and the projected impacts on Plummers Island. In November 2022 MDOT announced that it would not award a contract for construction of the proposed expansion project until after Governor Hogan has left office in January 2023. Decisions on the project will be made by the administration of newly elected governor Wes Moore and the Maryland Board of Public Works . In August 2023, MDOT applied for

10989-819: The time of the Warring States period , the oldest surviving stone bridge in China is the Zhaozhou Bridge , built from 595 to 605 AD during the Sui dynasty . This bridge is also historically significant as it is the world's oldest open-spandrel stone segmental arch bridge. European segmental arch bridges date back to at least the Alconétar Bridge (approximately 2nd century AD), while the enormous Roman era Trajan's Bridge (105 AD) featured open-spandrel segmental arches in wooden construction. Rope bridges ,

11100-748: The undertimbers of bridges all around the world are spots of prevalent graffiti. Some bridges attract people attempting suicide, and become known as suicide bridges . The materials used to build the structure are also used to categorize bridges. Until the end of the 18th century, bridges were made out of timber, stone and masonry. Modern bridges are currently built in concrete, steel, fiber reinforced polymers (FRP), stainless steel or combinations of those materials. Living bridges have been constructed of live plants such as Ficus elastica tree roots in India and wisteria vines in Japan. Unlike buildings whose design

11211-517: The variation of strength found in natural stone. One type of cement, called pozzolana , consisted of water, lime , sand, and volcanic rock . Brick and mortar bridges were built after the Roman era , as the technology for cement was lost (then later rediscovered). In India, the Arthashastra treatise by Kautilya mentions the construction of dams and bridges. A Mauryan bridge near Girnar

11322-433: The weld transitions . This results in a potential high benefit, using existing bridges far beyond the planned lifetime. While the response of a bridge to the applied loading is well understood, the applied traffic loading itself is still the subject of research. This is a statistical problem as loading is highly variable, particularly for road bridges. Load Effects in bridges (stresses, bending moments) are designed for using

11433-649: The word for the card game of the same name is unknown.   The simplest and earliest types of bridges were stepping stones . Neolithic people also built a form of boardwalk across marshes ; examples of such bridges include the Sweet Track and the Post Track in England, approximately 6000 years old. Ancient people would also have used log bridges consisting of logs that fell naturally or were intentionally felled or placed across streams. Some of

11544-452: The world and the longest railroad stone bridge. It was completed in 1905. Its arch, which was constructed from over 5,000 tonnes (4,900 long tons; 5,500 short tons) of stone blocks in just 18 days, is the second-largest stone arch in the world, surpassed only by the Friedensbrücke (Syratalviadukt) in Plauen , and the largest railroad stone arch. The arch of the Friedensbrücke, which was built in

11655-428: The world as a method of financing new or refurbished public sector assets outside their balance sheet . While PPP financing comes from the private sector, these projects are always paid for either through taxes or by users of the service, or a mix of both. PPPs are structurally more expensive than publicly financed projects because of the private sector's higher cost of borrowing, resulting in users or taxpayers footing

11766-439: Was down to 45.4%. Performance monitoring is a general concern from these surveys and in the scholarly criticisms of these arrangements." After a wave of privatization of many water services in the 1990s, mostly in developing countries, experiences show that global water corporations have not brought the promised improvements in public water utilities. Instead of lower prices, large volumes of investment, and improvements in

11877-454: Was no more efficient than other forms of borrowing and it was "illusory" that it shielded the taxpayer from risk'. One of the main rationales for P3s is that they provide for a transfer of risk : the Private partner assumes the risks in case of cost overruns or project failures. Methods for assessing value-for-money rely heavily on risk transfers to show the superiority of P3s. However, P3s do not inherently reduce risk, they simply reassign who

11988-527: Was opened; it is also the longest wooden bridge in Switzerland. The Arkadiko Bridge is one of four Mycenaean corbel arch bridges part of a former network of roads, designed to accommodate chariots , between the fort of Tiryns and town of Epidauros in the Peloponnese , in southern Greece . Dating to the Greek Bronze Age (13th century BC), it is one of the oldest arch bridges still in existence and use. Several intact, arched stone bridges from

12099-514: Was surveyed by James Princep . The bridge was swept away during a flood, and later repaired by Puspagupta, the chief architect of emperor Chandragupta I . The use of stronger bridges using plaited bamboo and iron chain was visible in India by about the 4th century. A number of bridges, both for military and commercial purposes, were constructed by the Mughal administration in India. Although large bridges of wooden construction existed in China at

12210-531: Was to promote and implement PFI. PUK was central in making PPPs the "new normal" for public infrastructure procurements in the country. Multiple countries subsequently created similar PPP units based on PUK's model. While initiated in first world countries , PPPs immediately received significant attention in developing countries . This is because the PPP model promised to bring new sources of funding for infrastructure projects in transition economies , which could translate into jobs and economic growth . However,

12321-495: Was widened from its original 6-lane configuration to the current 10-lane version by 1992 via a third span filling the median between what was originally two separate spans. The American Legion Memorial Bridge is an important commuter route because of its proximity to edge cities and high tech centers in Maryland and Virginia . It is the only high volume crossing between Montgomery County, Maryland and Fairfax County, Virginia,

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