742 research outputs found
Towards the Green Environment.Comparison of Environmental Impacts of Urban Public Transport and Automobiles
This study compares the environmental impacts of urban public transport and automobiles (energy use, emissions, noise nuisance, waste materials and use of space). For this purpose two models have been developed FACTS-Urban (Forecasting air pollution by car traffic simulation) and MILOV (environmental impacts of PT). Current Dutch situation as well as future scenarios on the demand side and the (technological) supply side have been studied. Generally speaking PT (especially rail) is and will remain cleaner than the use of the car. However, the environmental advantage of Diesel buses over passenger cars is diminishing rapidly.Emissions, Public transport, Policy
Effects of Transit Signal Priority on Traffic Safety: Interrupted Time Series Analysis of Portland, Oregon, Implementations
Transit signal priority (TSP) has been implemented to transit systems in many
cities of the United States. In evaluating TSP systems, more attention has been
given to its operational effects than to its safety effects. Existing studies
assessing safety effects of TSP reported mixed results, indicating that the
safety effects of TSP vary in different contexts. In this study, TSP
implementations in Portland, Oregon, were assessed using interrupted time
series analysis (ITSA) on month-to-month changes in number of crashes from
January 1995 to December 2010. Single-group and controlled ITSA were conducted
for all crashes, property-damage-only crashes, fatal and injury crashes,
pedestrian-involved crashes, and bike-involved crashes. Evaluation of the
post-intervention period (2003 to 2010) showed a reduction in all crashes on
street sections with TSP (-4.5 percent), comparing with the counterfactual
estimations based on the control group data. The reduction in
property-damage-only crashes (-10.0 percent) contributed the most to the
overall reduction. Fatal and injury crashes leveled out after TSP
implementation but did not change significantly comparing with the control
group. Pedestrian and bike-involved crashes were found to increase in the
post-intervention period with TSP, comparing with the control group. Potential
reasons to these TSP effects on traffic safety were discussed.Comment: Published in Accident Analysis & Preventio
Linking microsimulators of bus stops and traffic operations: the case of PASSION and BusSIGSIM
The aim of this article is to explore the linkage of two microsimulators developed at theUniversity College London. At present, these models deal independently with buses ateither bus stops or traffic networks. First, both microsimulators are described in somedetail. The generic way in which both models can be connected is then proposed. As aresult of this analysis, the main issues for a comprehensive introduction of public transportvehicles (buses) into microscopic traffic simulators are highlighted. One practical outcomeof this study is that the improvement in the representation of buses in microscopic trafficsimulators will allow the engineers to take into account traffic management measures thatotherwise will not be assessed
The Feasibility of Closing Vehicle Crossings along St. Charles Avenue: A Study of Transit Safety and Performance
The St. Charles streetcar is an important transit line in the city of New Orleans, with about 65,000 people living within a œ mile walking distance from it. However, the line experiences a very high streetcar/automobile crash rate due in large part to the large number of grade vehicle crossings over the tracks that lack signalization. Through traffic modeling, the closure of many of these vehicle crossings and the diversion of automotive traffic to the remaining, signalized crossings is analyzed to determine traffic impacts on street network. The result is a modest increase in traffic, about 7-8%, at the remaining signalized intersections
Energy and Transportation Policy
This paper presents experimental data which exemplifies the differences in emission level testing on internal combustion engines when dynamic engine tests are used instead of steady-state engine tests. A comparison of the two test methods is made using hydrocarbon fuels with varying amounts of methanol. Emissions measured include the nitric oxides, unburned hydrocarbons and carbon monoxide. Emission levels and fuel consumption are reported for the various volumetric percentages of methanol in the fuel.
Of special significance are the different trends the emission levels establish when subjected to a dynamic engine test as compared to the results for the steady-state tests. Dynamic tests provide a realistic automobile simulation (accelerations and decelerations) while maintaining the laboratory testing accuracy
Economic Impacts of Bus Rapid Transit in Southeast Michigan
In recent years, Bus Rapid Transit (BRT) has generated great interest across the United States. There are more than 20 BRT systems in existence, and more are in the planning stage (including in Detroit). Within the next few years, BRT will be planned and implemented phase by phase in various parts of Southeast Michigan. The purpose of this study is to develop a framework to identify probable economic impacts of BRT in Southeast Michigan.
Taxable real estate values, injury and fatal crash data, and selected demographics of BRT users, including employment sector, age group, median income, and daily vehicle miles traveled were reviewed to identify Southeast Michiganâs current and future trends.
The project team also performed shift-share analysis using Cleveland and Kansas City data to determine the BRT-advantaged age group. The authors recommended a number of action items to attract choice riders and gratify riders who must rely on BRT, such as tax incentives, branding, guaranteed levels of service, etc. Based on the literature review and analysis of existing BRT-related data by the project team, BRT-advantaged job sectors and age groups within the Southeast Michigan region were identified. BRT will be implemented in phases. This will affect the amount, type, and timing of investments in BRT. Considering this uncertainty, the potential economic impacts as a function of type and amount of investment were discussed. It is to be noted that in order to achieve the projected results, the BRT system must be planned, designed, and implemented based on the unique attributes of the Southeast Michigan region rather than by copying a system that has achieved success in another region
Future âgreenerâ urban transport: accessible, mobile and resilient cities?
Geographers, amongst others, have been considering urban futures for some time now. They all try to conceptually understand what a âsustainable cityâ in Europe / the UK / globally might look like. oncepts such as liveable, âgreenâ, sustainable and resilient are being discussed, with carbon emissions and transitions, including from transport. Mobility (or what some authors call motility) is one strand, with lifecycle assessment of vehicles and fuels being applied . This article reviews visions and policies for more resilient urban transport
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