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• We evaluate the time-varying safety effects of speed cameras. • Speed cameras have significantly reduced the number of road accidents. • Safety effects of speed cameras experienced a sharp decrease after the installation. • Appropriate management is important to maintain the effectiveness of speed cameras. Introduction: Speed limit enforcement cameras provide an effective approach to reduce vehicle speeds and the number of road accidents. However, it is still unclear whether the safety effects of speed cameras show durability over long periods of time. This paper analyses how the effects of speed cameras on road accidents change over time. A total number of 771 camera sites and 4787 potential control sites are observed for a period of 18 years (1999–2016) across England. Method : Covariates such as road class, crash history, speed limit, and annual average daily traffic (AADT) are included in the data set. A difference in difference (DID) based propensity score matching (PSM) method is employed to select proper control sites and estimate the treatment effects. The safety effects of speed cameras are then evaluated from a long-term perspective. The post-treatment period is divided into four equal-length periods: early, medium 1 and 2, and late. Results and Conclusions : The results show that speed cameras have significantly reduced the number of road accidents near the camera sites. However, the effects vary across different time periods. The safety effects of speed cameras experienced a sharp decrease during the medium periods after an initial period of highly reduced accidents (medium 1: −53.1%, medium 2: −40.7%) and recovered slightly during the late period. In addition, to evaluate the criteria for selecting camera sites in the UK, we further investigated whether speed cameras at high risk sites have better safety performance. The results show that while safety effects at high risk camera sites also decreased during the medium periods, the reduction was smaller (medium 1: −20.8%, medium 2: −2.1%). Practical Applications : Appropriate road traffic regulations and management, as well as proper camera sites selection criterion, are important to maintain the effectiveness of speed cameras. [ABSTRACT FROM AUTHOR]

Summary: In this article, the authors proposed a model predictive based sliding mode control (MPSMC) based ramp metering (RM) strategy for highway traffic control. The strategy includes sliding mode control (SMC) which makes it immune to uncertainties and provides fast responses while the addition of model predictive Control (MPC) will provide optimality. Therefore, the RM strategy will simultaneously present real‐time applicability, robustness, and optimality. To provide optimality, a new quadratic objective function homogeneous to total time spent (TTS) is proposed, and for both the SMC and MPSMC based RM the authors will prove the closed‐loop asymptotic global stability of the strategy in the presence of disturbance and uncertainties with the help of the proposed cost function. This objective function is based on minimizing traffic dynamic deviations from desired values. The proposed RM control strategy was applied to M62 smart highway in England and results are compared with existing control measures in the highway, ALINEA and SMC‐based RM. The simulations show that MPSMC will approach optimal behavior and thus, outperforms ALINEA and SMC regarding queue length and average speed. Moreover, the SMC and MPSMC based RMs are innately robust against disturbances, therefore, both will provide better performance regarding congestion reduction compared with ALINEA. Finally, it will be shown that MPSMC can improve TTS performance by 39% with respect to ALINEA while presenting global asymptotic stability. [ABSTRACT FROM AUTHOR]

Researchers use observational benchmarks to assess racial disproportionality in police traffic stops. To date, there has been a deficiency of empirical research evaluating the effectiveness of observational benchmarks across time-of-day and in comparison to census data. This article is a research note that reports the findings from analyses evaluating relative accuracy of daytime roadside observations in comparison with nighttime observations. Results indicate that daytime observations are more valid than nighttime observations and that daytime benchmarks if formed from small localized geographical areas are similar to residential census population data. The implications of these findings are discussed. [ABSTRACT FROM AUTHOR]

Background The red squirrel population in Great Britain has declined dramatically in recent decades, principally due to squirrelpox. Concern exists that red squirrels may become extinct nationally and, as there has been limited research in to diseases other than squirrelpox, this study aimed to identify additional causes of mortality. Results Post-mortem examinations on 163 red squirrels found dead on Isle of Wight (IoW) England, in Scotland and at other locations in Great Britain showed that 41.7% (n = 68) were killed by road traffic and 9.2% (n = 15) by predators, principally domestic cats and dogs. The overall male/female ratio was 1.08/1. Fleas were recorded on 34.9% of IoW squirrels and on 43.8% of Scottish squirrels but sucking lice and ixodid ticks were only seen on Scottish squirrels. Bacterial infections were significant, particularly in association with respiratory disease (n = 16); two squirrels died of Bordetella bronchiseptica bronchopneumonia. Cases of fatal exudative dermatitis (n = 5) associated with a lukM-positive clone of Staphylococcus aureus occurred only on the IoW. Toxoplasmosis (n = 12) was also confined to IoW where it was responsible for almost one sixth (15.6%) of all deaths. Hepatozoonosis was common, especially in IoW squirrels, but was not considered a primary cause of mortality. Hepatic capillariasis affected four IoW squirrels and one from Scotland. Fungal infections included oral candidiasis, adiaspiromycosis and pulmonary phaeohyphomycosis. Neoplastic conditions diagnosed were: pulmonary carcinoma, gastric spindle cell tumour, renal papillary adenoma and trichoepithelioma. Epidermal hyperplasia of unknown aetiology was seen in squirrels showing crusty lesions of the ear pinnae on IoW (n = 3) and Brownsea Island (n = 1), associated in two cases with cutaneous wart-like growths. Miscellaneous diagnoses included chylothorax, electrocution, intussusception, suspected cholecalciferol rodenticide poisoning and foetal death and mummification. No cases of squirrelpox were diagnosed. Conclusions Red squirrels in Britain suffer premature or unnatural mortality due to a number of conditions in addition to squirrelpox, many of which result, directly or indirectly, from human activities: road traffic trauma, pet predation, toxoplasmosis, trap injuries, rodenticide poisoning and electrocution accounted for 61% of all recorded mortality in this study. Red squirrels are also affected by several diseases of unknown aetiology which merit further research. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate the impact of the five strikes on the London Underground (metro) rail system, which occurred in 2009 and 2010, on macroscopic and road link travel times. A consequence of these strikes was an increase in road traffic flows above usual levels. This provides an opportunity to observe the operation of the road network under unusually high flows. The first objective involves the examination of strike effects on inbound (IT) and outbound traffic (OT) within central, inner and outer London. Travel time data obtained from automatic number plate recognition cameras are used within the first part of the analysis. The second more detailed objective was to investigate in spatio-temporal effects on travel times on five road links. Correlation analyses and general linear models are developed using both traffic flow and travel time data. According to the results of the study, the morning IT had approximately twice as much delay as the OT. Central London experienced the highest delays, followed by inner and outer London. As would be expected, the unique full-day strike in 2009 yielded the worst impact on the network with the highest percentage increase in total travel time (60%) occurring during the morning peak in the IT in inner London. The results from the link-level analysis showed statistical significance amongst the examined links indicating heterogeneous effects from one link to another. It was also found that travel time changes may be more effectively captured through time-of-day terms compared to hourly traffic flows. [ABSTRACT FROM AUTHOR]

Abstract: Macroscopic fundamental diagrams (MFD) of traffic for some networks have been shown to have similar shape to those for single links. They have erroneously been used to help estimate the level of travel in congested networks. We argue that supply curves, which track vehicles in their passage through congested networks, are needed for this purpose, and that they differ from the performance curves generated from MFD. We use a microsimulation model, DRACULA and two networks, one synthesizing the network for Cambridge, England, and one of the city of York, England, to explore the nature of performance curves and supply curves under differing patterns of demand. We show that supply curves differ from performance curves once the onset of congestion is reached, and that the incorrect use of performance curves to estimate demand can thus seriously underestimate traffic levels, the costs of congestion, and the value of congestion relief measures. We also show that network aggregated supply curves are sensitive to the temporal distribution of demand and, potentially, to the spatial distribution of demand. The shape of the supply curve also differs between origin–destination movements within a given network. We argue that supply curves for higher levels of demand cannot be observed in normal traffic conditions, and specify ways in which they can be determined from microsimulation and, potentially, by extrapolating observed data. We discuss the implications of these findings for conventional modelling of network management policies, and for these policies themselves. [Copyright &y& Elsevier]

Real time traffic flow simulation models are used to provide traffic information for dynamic traffic management systems. Those simulation models are supplied by traffic data in order to estimate and predict traffic conditions in unobserved sections of a traffic network. In general, most of recent real time traffic simulators are based on the macroscopic model because the macroscopic model replicates the average traffic behavior in terms of observable variables such as (time-space) flow and speed at a relatively fast computational time. Like other simulation models, an important aspect of the real time macroscopic simulator is to calibrate the model parameters online. The most conventional way of the online calibration is to add a random walk to the parameters to constitute an augmentation of the traffic variables and the model parameters to be estimated. Actually, this method allows the parameters to vary at every time step and, therefore, describes the adaptation of the model to the prevailing traffic conditions. However, it has been reported that the use of the random walk results in a loss of information and an increase of the covariance of parameters, which consequently leads to posteriors that are far more diffuse than the theoretical posteriors for the true parameters. To this end, this article puts forward a Kernel density estimation technique in the calibration process to handle the covariance issue and to avoid the information loss. The Kernel density estimation technique is embedded in the particle filter algorithm, which is extended to the calibration problems. The proposed framework is investigated using real-life data collected in a freeway in England. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this paper is to take a holistic perspective to explore levels of cycling and opportunities and barriers to increase children’s safer cycling in disadvantaged areas in England. The study was one part of a larger study which explored the factors underlying the high level of road traffic casualties especially among children in the most disadvantaged areas of England and to explore how this impacts on mobility and quality of life. The methods involved a cross sectional survey comprising school based questionnaire surveys with children aged 9–14 and focus groups with parents who had children within this age range. The surveys were conducted in 2007 and the focus groups during 2008. 4286 children completed the survey and eight focus groups were held. Bike ownership (77%) was high, use in previous week moderate (39%) but only 2% cycled to school. Ownership was significantly lower in minority ethnic groups. Despite young children’s strong preference to travel by cycle (30%) than walk or go by car, most parents felt it was too hazardous. It is unlikely that these findings would be any different from the rest of England, however the combination of environmental and social factors may elevate the risks for young cyclists in these areas. This paper concludes that a number of barriers exist to increasing levels of cycling among children living in disadvantaged areas particularly amongst ethnic groups. These barriers could be addressed by environmental modifications to reduce speeds and by reducing the levels of antisocial driving and riding in residential areas and around destinations where children travel, by providing cycle training to improve children’s skills and parent’s confidence, and by providing secure storage facilities for bikes. Until these barriers are addressed it is unlikely that cycling will increase despite the strong preferences children have to travel by bike. Such preferences to cycle provide an opportunity for local authorities to act on. [Copyright &y& Elsevier]

Abstract: This paper examines how complex transport projects are reported in the media using the Transport Innovation Fund bid for Greater Manchester as a case study. It demonstrates how projects are simplified and distorted in the media in a systematic way. Such distortion is explained by a scheme’s perceived newsworthiness, its complexity and the contemporary nature of news media production. The paper has implications for future research in this area and the implementation of sustainable transport policy. It urges transport professionals to both better understand, and engage directly with, the media if they are to maximise the benefits of efforts to shape travel behaviour. [Copyright &y& Elsevier]

Developing a network for cycle traffic is a complex process, particularly in a dense and heavily motor trafficked city such as London. The London Cycle Network Plus has delivered cycle routes on strategic highways, and local cycling stakeholders have assisted in the design process through cycle route implementation and stakeholder plans. Stakeholders were trained in aspects of highway engineering and used the London cycling design standards as a reference tool. The paper summarises the lessons learnt, and concludes that knowledge from stakeholders is needed to help in the design process, and such intense involvement was novel in transport planning. The current proposals for cycle superhighways and other borough transport schemes seek to build on previous participative successes and also emphasise planning issues in the geographical neighbourhood of routes. [ABSTRACT FROM AUTHOR]

In an ageing society older people have a growing influence on politics in general, and potentially on the acceptability of road charging in particular. They face specific types of risk of transport-related social exclusion which may influence their views on charging, although there is also evidence to suggest that older people favour, more than any other age group, what is positively valued by society - a process known as 'pro-social value orientation'. Family and friends may also affect older people's considerations about their intentions and choices - thus the importance of studying the influence of 'social norms' on older people's attitudes to road charging. The paper develops our understanding of these issues, based on the findings of a quantitative survey conducted in Bristol, UK. Evidence indicates that the attitudes of older people to road charging do differ from those of younger people and that pro-social value orientations and social norms do contribute to the formation of these attitudes. It is concluded that the presence of pro-social attitude orientations assists in explaining why people assumed to be 'natural supporters' of charging schemes may hold negative attitudes, which underlines to scheme promoters the importance of understanding and overcoming strongly held, psychologically complex objections. [ABSTRACT FROM AUTHOR]

Abstract: How much can we tell about flows through networks just from their topological properties? Whereas flow distributions of river basins, trees or cardiovascular systems come naturally to mind, more complex topologies are not so immediate, especially if the network is large and heterogeneously directed. Our study is motivated by the question of how the distribution of path-dependent trails in directed networks is correlated to the distribution of network flows. As an example we have studied the path-dependencies in closed trails in four metropolitan areas in England and the USA and computed their global and spatial correlations with measured traffic flows. We have found that the heterogeneous distribution of traffic intensity is mirrored by the distribution of agglomerate path-dependency and that high traffic roads are packed along corridors at short-to-medium trail lengths from the ensemble of nodes. [ABSTRACT FROM AUTHOR]

The origins of a road user charging concept for central London and the development of the central London congestion charging scheme are outlined. The paper then explains the objectives and the main features of Transport for London's programme of impacts monitoring of the scheme. It summarises the main results that were obtained. Drawing on the extensive data from the monitoring programme, the paper then compares the patterns of congestion and traffic flows that were observed in the original scheme and in its western extension. This shows how congestion was initially eased as traffic levels were reduced and how it subsequently increased as the effective capacity of the road network was reduced or reallocated. The paper concludes with some reflections on the achievements of the charging scheme. [ABSTRACT FROM AUTHOR]

Background: Cycling is an increasingly important mode of transport for environmental and health reasons. Cycling fatalities in London were previously investigated in 1994 using routinely collected data. Since then, there have been shifts in the modes of transport used, and in transport policies. We sought to replicate the previous work using data on cyclist deaths in London between 1992 and 2006, specifically investigating whether heavy goods vehicles continued to pose a threat. Methods: Observational study based on analysis of time series of police road casualties data, 1992 to 2006, in London, UK. The main outcome measures were cyclists killed in road traffic collisions. Poisson regression and chisquared test for homogeneity were used to assess time effects. Travel flow data was then used to estimate annual fatality rates per 100,000 cyclists per kilometre. Results: From 1992 to 2006 there was a mean of 16 cycling fatalities per year (range 8-21). 146 deaths (60%) were in inner London and 96 in outer London. There was no evidence for a decline over time (p = 0.7) other than a pronounced dip in 2004 when there were 8 fatalities. Freight vehicles were involved in 103 of 242 (43%) of all incidents and the vehicle was making a left turn in over half of these (53%). The fatality rate ranged from 20.5 deaths in 1992 to 11.1 deaths in 2006 per 100,000 estimated cyclists per kilometre (rate ratio 0.54, 95% confidence interval 0.28 to 1.03). Conclusions: There is little evidence fatality rates have fallen. Freight vehicles over 3.5 tonnes continue to present a disproportionate threat; they should be removed from urban roads and more appropriate means of delivery of essential goods found. [ABSTRACT FROM AUTHOR]

Route selection in metropolises based on specific desires is a major problem for city travelers as well as a challenging demand of car navigation systems. This paper introduces a multiparameter route selection system which employs fuzzy logic (FL) for local pheromone updating of an ant colony system (ACS) in detection of optimum multiparameter direction between two desired points, origin and destination (O/D). The importance rates of parameters such as path length and traffic are adjustable by the user. In this system, online traffic data are supplied directly by a traffic control center (TCC) and further minutes traffic data are predicted by employing artificial neural networks (ANNs). The proposed system is simulated on a region of London, United Kingdom, and the results are evaluated. [ABSTRACT FROM AUTHOR]

Abstract: The paper describes a field study focused on the dispersion of a traffic-related pollutant within an area close to a busy intersection between two street canyons in Central London. Simultaneous measurements of airflow, traffic flow and carbon monoxide concentrations ([CO]) are used to explore the causes of spatial variability in [CO] over a full range of background wind directions. Depending on the roof-top wind direction, evidence of both flow channelling and recirculation regimes were identified from data collected within the main canyon and the intersection. However, at the intersection, the merging of channelled flows from the canyons increased the flow complexity and turbulence intensity. These features, coupled with the close proximity of nearby queuing traffic in several directions, led to the highest overall time-average measured [CO] occurring at the intersection. Within the main street canyon, the data supported the presence of a helical flow regime for oblique roof-top flows, leading to increased [CO] on the canyon leeward side. Predominant wind directions led to some locations having significantly higher diurnal average [CO] due to being mostly on the canyon leeward side during the study period. For all locations, small changes in the background wind direction could cause large changes in the in-street mean wind angle and local turbulence intensity, implying that dispersion mechanisms would be highly sensitive to small changes in above roof flows. During peak traffic flow periods, concentrations within parallel side streets were approximately four times lower than within the main canyon and intersection which has implications for controlling personal exposure. Overall, the results illustrate that pollutant concentrations can be highly spatially variable over even short distances within complex urban geometries, and that synoptic wind patterns, traffic queue location and building topologies all play a role in determining where pollutant hot spots occur. [Copyright &y& Elsevier]

Chassis dynamometer driving cycles designed to quantify vehicle emissions often miss the extremes in driver behaviour. The vehicle emissions measured during these driving cycles are used for modelling and policy purposes. To better understand the impact of omitting such extremes, two drivers were asked to follow a set of behavioural rules to replicate 'aggressive' and 'passive' driving styles along a real-world route in Southampton, UK. The test route included a wide range of traffic conditions that could be expected on urban roads. The resulting driving profiles were compared to a number of legislative driving cycles - this indicated that aggressive driving was poorly addressed by these cycles. When replicated on a chassis dynamometer, the aggressive profile produced carbon monoxide, oxides of nitrogen and carbon dioxide emission rates of 2·68, 0·853 and 183·6 g/km, respectively, whereas the passive profile produced only 0·064, 0·011 and 124·4 g/km, respectively. Non-inclusion of aggressive driving styles in legislative driving cycles will mean that driving events that lead to disproportionately high emissions are not addressed by legislation designed to improve overall vehicle emissions control performance (e.g. Euro standards). In addition, a proportion of vehicle emissions will be missed from the modelling process which may have implications for local authorities declaring Air Quality Management Areas. [ABSTRACT FROM AUTHOR]

Automobility lies at the heart of contemporary analysis of the social relations of mobility. Thus far, however, it lacks a history. This article seeks to rectify that omission by interrogating the road traffic accident crisis which afflicted Manchester in the early years of the Second World War. The article proposes a provisional chronology for automobility in twentieth-century Britain: a lengthy phase between 1920 and 1970, dominated by the interests of private motorists, and a modern sub-period between 1970 and the near present. The latter era witnessed a gradual, and then an increasingly rapid, movement towards meeting the needs of non-drivers. [ABSTRACT FROM AUTHOR]

In the early 1990s Cambridgeshire County Council considered the implementation of a road user charging scheme for the city of Cambridge, UK. This involved the trial of a congestion metering scheme, a form of road user charging. Cambridge presented an ideal opportunity for the implementation of a road user charging scheme not least in terms of its congestion problem, the free-standing nature of the city and the fact that at the time, the local authority in the form of the council was sympathetic to the objectives of road user charging. The scheme did not, however, proceed and many reasons have been put forward as to why this was the case—issues such as not all the alternatives having been exhausted, the level of sophistication of the proposed scheme and the lack of a similar scheme to consider elsewhere. Fifteen years later, Cambridgeshire is once again considering the whole issue of road user charging. As such, the aim of this paper is to assess how the authority is proceeding this time round: what type of technology is being considered; how the politicians are presenting the concept to the local population and what are they doing differently from the first time round, in terms of consultation; and most importantly, what provision for alternative means of transport will be made and how this relates to the potential success of any road user charging scheme? The paper aims to conclude on what lessons can be learnt in terms of other cities considering the implementation of a road user charging scheme. [ABSTRACT FROM AUTHOR]

The Victoria line, extended to Brixton by July 1971, was London's first completely new underground line since the 'tube boom' of the early twentieth century. The new line created connections between the underground and national rail networks, and relieved congestion on London's transport network. Three decades later, Brixton station was at the forefront of a new challenge, this time to improve accessibility of the London Underground network to disabled and encumbered passengers. In 2001 work began to provide step-free access from street to platform levels at Brixton station, to alleviate congestion within the station, and to harness additional benefits by constructing new office and retail facilities. This paper describes the construction, emergency preparedness, site safety, contract administration and assurance aspects of delivering the project. The project successfully executed demolition, building construction, structural, tunnelling and services works while maintaining the safe and effective operation of the station. A number of recommendations are made to assist in the execution of similar projects. [ABSTRACT FROM AUTHOR]

This paper sets out the safety and traffic management arrangements for one of the most prestigious events in the sports calendar, the PGA World Golf Championship, held for the first time in the UK in 2006. Hertfordshire Highways was responsible for ensuring that safety was maintained and gridlock avoided during the six-day event. This paper describes the meticulous planning arrangements prior to the event, as well as the coordination between the many organisations responsible for ensuring that traffic could enter and exit the various car parks and that plans were in place in the event of an emergency on site. The paper ends with lessons learned and considers what actions taken might be different if an event of this scale were to be held in Hertfordshire in the future. [ABSTRACT FROM AUTHOR]

The use of variable message signs (VMS) to provide traffic information is widespread, but success depends upon behavioural response to the sign messages. The research described here focuses on user acceptance of VMS located in an urban road network (Southampton, UK), and investigates the public's perceived effectiveness and usefulness of these signs through the use of revealed preference questionnaire surveys and travel diaries. Three hundred and sixty-five commuters regularly driving into Southampton from the outskirts of the city completed a travel diary for a 5-day period as well as a general questionnaire, and 660 infrequent travellers to Southampton completed the general questionnaire. The study showed that it is difficult to capture a meaningful sample size of respondents passing an ‘active’ VMS in a real-life incident scenario. Less than 1% of the commuter sample stated that they had diverted to an alternative route during the travel diary week as a result of VMS information, although this did correspond to 53% of those 45 drivers originally intending to travel past the incident location. The results showed that the VMS messages were well-understood and legible, and also indicated that a default VMS message reporting no problems in the network can indirectly affect a driver's route choice. [ABSTRACT FROM AUTHOR]

By the 1990s, the average speed of trips across London was below that at the beginning of the twentieth century--before the car was introduced--and by the end of that decade, public concern over levels of traffic congestion was high. In early 2003, London imposed a congestion charge--a daily charge for driving or parking a vehicle on public roads within central London between the hours of 7:00 a.m. and 6:30 p.m. on workdays. Traffic congestion has declined substantially, and the program is largely popular. This article describes the origins of the London congestion charge, how it overcame practical and theoretical difficulties, and what effects it has had. The introduction of the London congestion charge is, in important respects, a triumph of economics. It represents a high-profile public and political recognition of congestion as a distorting externality and of road pricing as an appropriate policy response. [ABSTRACT FROM AUTHOR]

The Highways Agency's National Traffic Control Centre (NTCC) became fully operational in November 2003. The services provided by the control centre are key to satisfying the objectives of providing better information to travellers and ensuring more reliable journeys. This paper describes the policy context within which the control centre has been delivered; the means by which it collects data on conditions on England's motorway and all-purpose trunk road network; how those data are analysed; and the means by which information is disseminated to the general public. These services are providing the catalyst for the development of traffic information delivery tools by the Agency and private sector information providers. [ABSTRACT FROM AUTHOR]

To date, studies of incidents on British motorways have been very limited. As part of a study into the role of Incident Support Units (ISUs) on the M25, the London orbital motorway, an analysis of road traffic incidents was undertaken. Motorway incident data were collected through closed circuit television (CCTV) observations at Surrey Police's Godstone Motorway Control Room. The collected data covered the Surrey Police section of the M25 motorway between Clacket Lane Services and Junction 14, for a four-week period between 5 November and 11 December 2003. Incident frequency, durations, locations, detection times, notification methods and ISU involvement were examined. It was found that the average incident frequency was 16.1 incidents per day for the study area, and the highest occurrence of incidents was found to be between 11.00 am and 12.00 pm. On average the recorded incidents lasted 1 h 9 min, with those occurring in the evening peak period lasting the longest. The distribution of incidents along the study area showed that the section between Junctions 9 and 10 had the highest rate for the study period. A comparison of incident characteristics between US and UK studies was also conducted. Incident rates between the M25 and the US were found to be substantially different, and incident durations were found to be between double and triple those of the US. Possible reasons for these differences are discussed in the text. [ABSTRACT FROM AUTHOR]

In January 2002, the UK Department for Transport (DIT) announced the 61 schemes that had been successful in sharing a £30 million grant allocation to develop the Home Zone concept throughout England. Eight pilot schemes in England and one in Wales were announced in August 1999 (together with four in Scotland one year later) and the Dif decided that the concept should be extended. Many of the UK's existing residential areas were not designed for the level of traffic, and particularly parking, that now takes place. As a consequence the streets in front of houses have become extended car parks and are perceived as dangerous for children. This has resulted in a breakdown of local communities as families become isolated within their properties. Children particularly are denied the opportunity of playing and mixing with friends in areas that also include traffic. The aim of the Challenge Programme is to develop residential communities where the streets are shared equally between traffic and residents and introduce different uses within the streets—particularly play. An important aspect of the development of these streets is that they should be designed such that vehicle speeds are kept down to between 10 and 15 mph. The local communities should also be actively involved in their design and development. This paper reviews the progress of these schemes to date and examines the various techniques that have been developed to engage the community fully in the design process. [ABSTRACT FROM AUTHOR]

Debates about whether traffic regulations that limit car use will enhance or hinder a particular urban economy are complex and often emotive. The present article considers evidence from the implementation of a radical traffic restraint and pedestrianisation scheme in Oxford in 1999. The most important achievement was a 17% reduction in car trips to the centre, which did not affect overall visitor numbers. The local economy did though experience a period of difficult trading around the time of implementation. [ABSTRACT FROM AUTHOR]

The present bridge over the River Dee at Chester is the principal thoroughfare between the great manufacturing districts of the North of England [and] Wales; and Shropshire, Herefordshire, the Western Counties and also Holyhead and Ireland. All the Coals for the supply of Chester and the districts to the North and East of it are brought over this bridge, as also the Iron of [Denbighshire], both in the pig and when manufactured into Boilers, Cylinders etc.; the Lead of Flintshire, the timber from Wales and Shropshire, and the Cheese of a very large extent of the Country. There are sixteen Stage-coaches passing it daily, besides all the Chaises, Gigs and Horses of the adjacent Country; it is a very great thoroughfare for Cattle, Sheep etc. and it is crowded with Foot Passengers, for whom there is not a side path. [ABSTRACT FROM AUTHOR]

Focuses on the implementation of economic initiatives in Hertfordshire, England. Development of Business TravelWise program in response to the potential traffic growth; Development of transport policies; Advantages brought by film production on the economy.

The allocation of funds to police authorities in England and Wales is based on a formula which has been constructed to capture the key drivers of the main activities of the police: crime management, call management, public order and reassurance and traffic management. The formula was based on data from a 1995/96 survey by the Association of Chief Police Officers (ACPO), using data on police activity and recorded crime from 1990–92. In this article, the authors argue that the resulting allocation no longer reflects accurately the policing needs of London. [ABSTRACT FROM AUTHOR]

The exposure to CO of schoolchildren was assessed in the town of Northampton, UK, both by direct measurement and by GIS-based activity modelling. Personal measurement of CO showed that exposures when travelling by car were significantly greater than those when walking, although journey times by car were shorter. However, journey exposures had little effect on maximum 8h mean CO exposures. CO concentration fields in the study area were modelled from current traffic flows, and those expected under different traffic management scenarios. These fields were then used, in combination with children's home and school location, and their activity profiles, to simulate frequency distributions of exposure for different transport modes and traffic management scenarios. The results show a large variability in the effect of traffic management interventions, depending on the child's home and school location. [ABSTRACT FROM AUTHOR]

The movement of traffic past a point is compared to the output of a queuing system having random input. A generalization of the queue output model leads to a suitable headway model: this model is a mixture of two distributions, representing following and nonfollowing headways, in appropriate proportions. This model is compared with, several others that have been suggested; when used with a lognormal distribution of following headways, it gives the best overall fit to data from the M4 motorway, England, and two-way roads in Indiana, USA. For each site, the parameters of the following headway distribution can be assumed constant. The mean following headways are 1.3 sec and 1.6 sec for the M4 fast and slow lanes respectively, and 2 sec for the Indiana sites. The standard deviation of logarithms of following headways is 0.4 for both M4 lanes and 0.45 for the Indiana sites. For most samples, the reciprocal of the mean interbunch gap λ can be approximated by λ = λ* - ½λ*&frac32;, where λ* is the flow rate, and the proportion of the following vehicles ψ can be approximated by ψ = ρ -- ½ (ρ- 1) λ*&frac32;, where ρ is the traffic intensity. [ABSTRACT FROM AUTHOR]

In order to ascertain whether neighboring intersections can be effectively coupled on the basis of traffic behavior, observational information on vehicular platoons was collected at four sites in London, England. This information is analyzed with particular emphasis on the phasing or synchronization of neighboring inter-sections for minimum delay. At each of the four sites studied, arrival time data was collected at four positions downstream from the signalized intersection from which the vehicular platoons were emerging. This data gives a measure of how platoons diffuse as they move from one intersection to the next. The analysis indicates that the diffusion process can be taken into account in the setting of signals. In particular, total delay in vehicle-hours per hour of green as a function of offset time is calculated, and in turn, the optimal offset time that would minimize delay is shown to be a linear function of the distance from the issuing traffic signal. [ABSTRACT FROM AUTHOR]

The article presents the results of shared surfaces research carried out by pedestrian accessibility and movement environment laboratory at University College London in England. It is outlined that this research is the third phase of a Guide Dogs for the Blind Association research programme that was initiated following growing concern that local authorities were redesigning town centres and high streets using the concept of shared space. This research has identified the effectiveness of each delineator in an internal controlled environment. The effects of lighting, weather and additional cognitive loading were not considered and would need to be the subject of further research.