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This study analyzed traffic congestion scenarios in underground roads diverging and merging sections and underground sections that run parallel to ground roads using a microscopic traffic simulation model. The appropriate ratio of the ramp inflow or outflow of traffic volume to the entry traffic volume at the starting section of the underground road network was analyzed. Furthermore, the effect of traffic operation such as adequate throughput, average traffic speed, occupancy, and volume versus capacity (V/C) ratios before the occurrence of traffic congestion in all three road networks was properly produced. To maintain a minimum level of service of all underground sections at the D–E level, the underground inflow traffic volume should be equal to approximately 70% of the 4000 pcph inflow traffic volume from an open road to the underground. The results of this study are a useful reference for establishing traffic control application standards to minimize underground traffic congestion. They also provide useful insights for underground road design. [ABSTRACT FROM AUTHOR]

A non‐recurring incident often negatively affects traffic, which is represented as non‐recurrent congestion. However, travellers can usually perceive congestion without knowing the underlying reasons. Accordingly, this paper proposes a data‐driven framework for non‐recurrent congestion detection and interpretation analysis. First, a statistical algorithm named generalized extreme studentized deviate is introduced to detect non‐recurrent congestion by comparing the current traffic speed with the speed threshold learned from historical data. The case study in Beijing shows that the proposed generalized extreme studentized deviate outperforms other prevailing algorithms in terms of detection rate, false alarm rate, and mean detection time. Second, data mining and natural language processing technologies are implemented on data collected from Sina Weibo, a Chinese microblog site akin to Twitter, to classify non‐recurring incidents that may be associated with non‐recurrent congestion, including traffic accident, road construction, concert, special sport (marathon), and commercial activity. Results show that overall classification accuracy reaches 95%. Finally, the association relationship between the detected non‐recurrent congestions and incidents is established via spatiotemporal information matching. This information matching provides a bidirectional verification. On the one hand, nearly 58% of non‐recurrent congestion can be explained by incident‐related (IR) microblogs. On the other hand, an average of 62% of IR microblogs can be traced by nearby non‐recurrent congestions. This paper suggests that social media can be used as a secondary source and integrated with traffic data to enhance the understanding of non‐recurrent congestion. [ABSTRACT FROM AUTHOR]

A road construction project has a significant effect on traffic congestion and operational performance of the project corridor and connecting street links. However, not many researchers focused on travel time performance-based measures to assess the effect of a road construction project on the project corridor and connecting street links. Therefore, travel time data for a freeway road resurfacing project on 100 links within its vicinity were gathered and processed to assess the effect on freeway and connecting arterial street links. A paired t-test was used to examine the differences in means between the before and during road resurfacing project period travel time performance-based measures. There is a significant difference in travel time performance-based measures before and during the road resurfacing project period on freeway links and connecting arterial links. Their significance varied by the time-of-the-day and day-of-the-week on the freeway and connecting arterial links. The average travel time, planning time, and travel time index can consistently explain the effect of a road resurfacing (construction) project on transportation system performance when compared to buffer time and buffer time index. The findings can be used to enhance temporary traffic control practices in the vicinity of road construction projects. [ABSTRACT FROM AUTHOR]

This work's searching subject are Banovici's local roads which represent mutually dependent municipality or town traffic system that is connected to regional or motorway road system, and uncategorized roads which represent every traffic area that is not categorized as public road. Also it gives a view of local and uncategorized roads but those that are built using macadam and flexible asphalt) road construction with given advantages and disadvantages of present built flexible constructions. This work also contains a maintenance review of macadam and flexible (asphalt) road constructions with given road maintenance costs annually. Road dimensioning construction has been done, optimal thickness and road construction level type has been obtained. The guideline method for designing and maintaining roads in B&H is the one by which dimensioning has been made considering the same embrace more familiar dimensioning methods but demanding more input details. These details start with traffic burden, groundwork capacity, project road characteristics, traffic burden estimate as well as other factors that have impact on traffic burden. Concerning given results, using parallel analyses the most optimal solution of local and uncategorized road traffic construction has been defined for a price of 1m2, so the specific conclusions have been made. [ABSTRACT FROM AUTHOR]

The ability and efficiency of abstracting highway operating status are determined by data collection cost, equipment reliability, and other factors. Thus it has always been a significant demand for low installation and maintenance cost, solid and efficient equipment with rational and reliable data analysis methodology, which corporately could provide accurate traffic prediction. This paper proposed a method for obtaining traffic situation based on widely used ETC dedicated short range communication (DSRC) device, and investigated its feasibility for dynamic highway operating status abstracting. In addition, some detailed operating index, such as section average travel time, average travel speed, etc., were estimated, and with these indexes, a highway section congestion degree model and a travel time prediction model were established. Furthermore, a pilot study on Jingjintang Expressway near Beijing was conducted, and the results of DSRC data exploring showed that the proposed traffic condition obtaining method could accurately reflect the actual traffic condition. [ABSTRACT FROM AUTHOR]

There is an incompatibility between how transport engineers think drivers behave in roadworks and how they actually behave. As a result of this incompatibility we are losing approximately a lane's worth of capacity in addition to those closed by the roadworks themselves. The problem would have little significance were it not for the fact a lane of motorway costs approx. £30 m per mile to construct and £43 k a year to maintain, and that many more roadworks are planned as infrastructure constructed 40 or 50 years previously reaches a critical stage in its lifecycle. Given current traffic volumes, and the sensitivity of road networks to congestion, the effects of roadworks need to be accurately assessed. To do this requires a new ergonomic approach. A large-scale observational study of real traffic conditions was used to identify the issues and impacts, which were then mapped to the ergonomic knowledge-base on driver behaviour, and combined to developed practical guidelines to help in modelling future roadworks scenarios with greater behavioural accuracy. Also stemming from the work are novel directions for the future ergonomic design of roadworks themselves. [ABSTRACT FROM AUTHOR]

Within the framework of this paper, the existence of a Macroscopic Fundamental Diagram (MFD) for the city of Thessaloniki is discussed, obtained through simulation. Initial findings show that there is a well-defined MFD, which is a property of a network, as it is not influenced by changes in travel demand. The MFD can be used as tool for managing traffic at real-time and for improving accessibility in an area, through pricing strategies and entrance points control based on the accumulation of vehicles. [ABSTRACT FROM AUTHOR]

Through trips are a concerns as these trips contribute to roadway congestion that must be accommodated, but for which there are no simple methods to determine. Concerns for safety and a need to avoid inconveniencing drivers have limited the use of traditional vehicle surveys. Previous research developed equations to estimate through trips in communities, requiring data on street locations, traffic volumes, community demographics, economic data and geographic data. Alternatively, using cell phones or Bluetooth devices to collect traveler information have not always been accepted by the general public and are often seen as intrusions into driver privacy. Transportation professionals are in need of a methodology to estimate through trips to improve the transportation planning process and better allocate resources for roadway infrastructure investment. This research utilizes roadway connectivity and traffic count data to estimate through trip numbers. The methodology determines through trips using roadway counts collected as part of a routine traffic monitoring procedure. The methodology has been tested against a community that underwent a Bluetooth data collection study. The outcome of this research will benefit any community with a traffic monitoring program where through trip patterns could be used to improve resource allocation. [ABSTRACT FROM AUTHOR]

Optimization of traffic on a large public road network is a complex task. Reversible direction lane theory is an interesting and special method within this subject. This can completely support the fluctuation or alteration of main congested directions existing in the traffic dynamics (time of day, seasonal, etc.) on the existing road surfaces. In such case, certain subsystems of the main network cease to exist, and subsystems working with new connections take their place. This type of routing therefore changes the structure of the system ‘in an optimal direction’, but many practical and safety questions arise. The authors have examined the modelling of a Reversible Lane System (RLS) created based on a simple part of a road network, which is segmented into elements. Functions of each network element and contacts between them cease operating in the course of such change while new contacts and new function elements are activated instead. The article presents the mathematical modelling of the problem. It points out the fundamental questions of the structure change and exemplifies the above using a simple example. The authors studied a general mathematical model describing the RLS. They examined the availability of the optimal control in a sample network depending on the traffic density, using a new principle, which responds to the dynamic change of the structure of the network graph. It can be shown, that the results from the model are in harmony with the real traffic values based on measurements made in road traffic systems working with RLS. [ABSTRACT FROM PUBLISHER]

The paper examines the adequacy and deficiency of transport planning in Lahore to recommend some measures for developing a sustainable urban transport system in the city. Urban transport is one of the most important sectors having a direct impact on sustainable development. The pattern of land use and the available transportation systems in urban areas play a critical role in determining the livability and sustainability of those urban areas. Land use planning and its integration with the transport planning is most ignored issue. Traffic management and roadway construction has not kept pace with the increased mobility needs of the society. Lahore city is being the cultural, intellectual, political and economic hub of the Punjab province, has experienced adverse impacts of traffic congestion and mismanagement. [ABSTRACT FROM AUTHOR]

This research investigates the design and impact of a new travel demand management approach, namely the Downtown Space Reservation System (DSRS), using a microscopic traffic simulation approach executed in VISSIM. The DSRS is part of a Travel Demand Management strategy that is designed to mitigate traffic congestion in a downtown urban setting. The simulation is conducted according to an experimental design procedure for a revised road network representing downtown Boise, Idaho. The issues that are tested in the simulation include: (1) whether the DSRS improves traffic performance when compared with the case without the DSRS; (2) how the DSRS performs compared with a reservation system that uses a First Come First Serve principle; and (3) how the specific DSRS parameters (such as, the relative importance of throughput versus revenue generation) influence network system performance. Conclusions and future research recommendations are provided based on the insights from the simulation modeling work. [ABSTRACT FROM AUTHOR]

The Bahrain Ministry of Works roads directorate and Hyder Consulting undertook a national transport model in 2002 in which traffic congestion was identified and future 2021 traffic flows were estimated. Strategic improvements were identified to improve traffic flow and make allowances for future increases in traffic volumes. The Isa Town Gate interchange was an existing roundabout with a five-leg junction in an urban setting with two major highways: Sheikh Salman Highway and Al Estiqlal Highway. This paper details the design of the £66 million project from concept to tender and also expands on the construction progress. Execution of the project modified the existing Isa Town Gate roundabout into a three-level grade-separated interchange. The option chosen was a three-level grade-separated junction with a free-flow flyover and underpass for the major highway routes. The existing roundabout was replaced with a complex split-traffic signalised junction accommodating all movements. The flyover consisted of two non-parallel curved bridge decks 2·4 km long of glued segmental prestressed concrete viaducts. An overhead launching gantry was specified to minimise traffic management. The underpass was designed as a diaphragm-walled U trough but was later varied to a ground-anchored solution. Construction commenced in October 2007, and is due for completion in mid-2010. [ABSTRACT FROM AUTHOR]

Abstract: The problem of determining link tolls to reduce traffic congestion is often referred as a toll design problem. In this paper, optimal tolls are determined for signal-controlled junctions in urban traffic road networks where the rerouting traffic is properly taken into account. This problem can be formulated as a mathematical program with equilibrium constraints (MPEC) where the user equilibrium is expressed as a variational inequality problem. Due to the non-differentiability of the equilibrium problem, an efficient convergent solution scheme is established. Numerical calculations are conducted on a variety of example road networks and comparisons are made with earlier methods. [Copyright &y& Elsevier]

Signal control strategies for congested urban road networks designed in a centralized framework require many communication links, serious processing power, and infrastructure for the centralized coordination. As a result, strategies based on a centralized framework are not scalable. The use of decentralized signal control strategies for large-scale urban traffic networks is a solution to this problem, since it allows for the implementation of such strategies on networks whose centralized solution is not easily scalable. This paper addresses the problem of designing a decentralized traffic-responsive signal control solution, proposing two methods based on different formulations of the store-and-forward model: (i) the Decentralized Traffic-responsive Urban Control (DTUC) method; and (ii) the Decentralized Decoupled Traffic-responsive Urban Control (D2TUC). The decentralized configuration is such that each intersection is associated with one computational unit, with limited computational power and memory, which controls the traffic signals of the incoming links. Sufficient conditions for the controllability of the considered store-and-forward models are also presented. Both methods are validated resorting to numerical simulations of the urban traffic network of Chania, Greece, for two demand scenarios, and their performance is compared with the performance of the Traffic-responsive Urban Control (TUC) centralized strategy. One of the proposed decentralized methods, D2TUC, is shown to match the performance of TUC. • Design of decentralized signal control solutions based on the store-and-forward model. • Sufficient controllability conditions for the store-and-forward model are presented. • Two decentralized solutions are synthesized considering the network globally. • Validation resorting to numerical simulations of the traffic network of Chania. • One of the proposed decentralized solutions, D2TUC, matches the performance of TUC. [ABSTRACT FROM AUTHOR]

This article reviews explanations of, and international empirical evidence for, 'induced' traffic as a result of increased road capacity and 'suppressed' traffic as a result of decreased road capacity. In essence, the former refers to new traffic appearing as a result of new road construction, while the latter refers lo traffic disappearing as a result of road closure. Despite problems with the available data and their measurement, it is concluded that - with the caveats of either pre-existing congestion in the case of capacity increases or no spare capacity in the case of capacity decreases - the weight of evidence indicates that induced and suppressed traffic are indeed real phenomena. It is argued that the link between traffic and road capacity is therefore far more complex than previously understood. The implications this has for both urban passenger transport planning practice and policy formulation are discussed. [ABSTRACT FROM AUTHOR]

The article discusses whether the Department of Transport's justification of several inter-urban motorway schemes ensure value for money for Great Britain's roads program as a whole in 1983. Key issues discussed include the key role of the road improvement and construction programs to the economic growth of Great Britain, the benefits of the projects in terms of reduced traffic congestion, the possibility of overstating the benefits of the programs and the issue's implications for the country's transportation policy. INSET: Evaluation Methods.

In this article Don Mathew examines the continuing tension between official policy-makers and proponents of alternative transport solutions which are broader based, more accessible and more environmentally aware. In many areas there is mounting concern that the large road-building programmes currently planned will exacerbate, rather than solve, existing traffic problems. Reactions to these programmes have converged to produce a 'new realism' in transport thinking. [ABSTRACT FROM AUTHOR]

Tackles the controversies surrounding highway construction in the U.S. Correlation between highway construction and traffic congestion; Findings of a study on highway construction projects and traffic engineering; Implications of the issues surrounding highway construction for engineers.