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Driving Among High School Students — United States, 2013

April 6, 2015 Comments off

Driving Among High School Students — United States, 2013
Source: Morbidity and Mortality Weekly Report (CDC)

During 2004–2013, the number of passenger vehicle drivers aged 16–19 years involved in fatal crashes in the United States declined by 55% from 5,724 to 2,568.* In addition to graduated driver licensing (GDL) programs (1) and safer vehicles,† other possible contributors to the decline include adolescents waiting longer to get their driver licenses and driving less (2). The crash risk for drivers of any age is highest during the first months of independent driving, and this risk is highest for the youngest teenage drivers (3). To estimate the percentage of high school students aged ≥16 years who have driven during the past 30 days, by age, race/ethnicity, and location, CDC analyzed 2013 data from the national Youth Risk Behavior Survey (YRBS) and YRBS data collected by 42 states and 21 large urban school districts. Nationwide, 76.3% of high school students aged ≥16 years reported having driven during the 30 days before the survey; 83.2% of white students had driven compared with <70% of black and Hispanic students. Across 42 states, the percentage of students who drove ranged from 53.8% to 90.2%. Driving prevalence was higher in the midwestern and mountain states. Across the 21 large urban school districts, the percentage of drivers varied more than twofold from 30.2% to 76.0%. This report provides the most detailed evidence to date that the percentage of students who drive varies substantially depending on where they live. Such information will be vital as states and communities consider potential ways to improve safety for older teenage novice drivers and plan for safe, affordable transportation options for those who do not drive.

Road Safety with Self-Driving Vehicles: General Limitations and Road Sharing with Conventional Vehicles

April 6, 2015 Comments off

Road Safety with Self-Driving Vehicles: General Limitations and Road Sharing with Conventional Vehicles (PDF)
Source: University of Michigan Transportation Research Institute

Self-driving vehicles are expected to improve road safety, improve the mobility of those who currently cannot use conventional vehicles, and reduce emissions. In this white paper we discuss issues related to road safety with self-driving vehicles. Safety is addressed from the following four perspectives: (1) Can self-driving vehicles compensate for contributions to crash causation by other traffic participants, as well as vehicular, roadway, and environmental factors? (2) Can all relevant inputs for computational decisions be supplied to a self-driving vehicle? (3) Can computational speed, constant vigilance, and lack of distractibility of selfdriving vehicles make predictive knowledge of an experienced driver irrelevant? (4) How would road safety be influenced during the expected long transition period during which conventional and self-driving vehicles would need to interact on the road?

The presented arguments support the following conclusions: (1) The expectation of zero fatalities with self-driving vehicles is not realistic. (2) It is not a foregone conclusion that a self-driving vehicle would ever perform more safely than an experienced, middle-aged driver. (3) During the transition period when conventional and self-driving vehicles would share the road, safety might actually worsen, at least for the conventional vehicles.

Hidden Benefits of Electric Vehicles for Addressing Climate Change

April 4, 2015 Comments off

Hidden Benefits of Electric Vehicles for Addressing Climate Change
Source: Scientific Reports

There is an increasingly hot debate on whether the replacement of conventional vehicles (CVs) by electric vehicles (EVs) should be delayed or accelerated since EVs require higher cost and cause more pollution than CVs in the manufacturing process. Here we reveal two hidden benefits of EVs for addressing climate change to support the imperative acceleration of replacing CVs with EVs. As EVs emit much less heat than CVs within the same mileage, the replacement can mitigate urban heat island effect (UHIE) to reduce the energy consumption of air conditioners, benefitting local and global climates. To demonstrate these effects brought by the replacement of CVs by EVs, we take Beijing, China, as an example. EVs emit only 19.8% of the total heat emitted by CVs per mile. The replacement of CVs by EVs in 2012 could have mitigated the summer heat island intensity (HII) by about 0.94°C, reduced the amount of electricity consumed daily by air conditioners in buildings by 14.44 million kilowatt-hours (kWh), and reduced daily CO2 emissions by 10,686 tonnes.

New TomTom data reveals rush hour traffic doubles journey times for commuters

April 1, 2015 Comments off

New TomTom data reveals rush hour traffic doubles journey times for commuters
Source: TomTom

TomTom (TOM2) today releases its annual Traffic Index highlighting the impact of traffic congestion in over 200 cities around the world. TomTom data reveals that traffic congestion nearly doubles journey times during the evening rush hour. In 2014, the average commuter spent an extra 100 hours a year travelling during the evening rush hour alone.

According to TomTom Traffic data, the evening rush hour is the most congested time of day. Nearly every city with the highest overall levels of congestion can expect to double their congestion level during the evening rush hour.

Commuters in Istanbul experience the worst traffic congestion overall, the evening rush hour is no exception. The average 30 minute drive in the city will take over an hour during evening rush hour, leading to an extra 125 hours wasted stuck in traffic every year. In Los Angeles, a 30 minute commute in the evening will take 54 minutes due to congestion, an extra 92 hours annually.

Safer Streets, Stronger Economies

March 30, 2015 Comments off

Safer Streets, Stronger Economies
Source: Smart Growth America

What do communities get for their investments in Complete Streets? In this study of 37 projects, Smart Growth America found that Complete Streets projects tended to improve safety for everyone, increased biking and walking, and showed a mix of increases and decreases in automobile traffic, depending in part on the project goal. Compared to conventional transportation projects, these projects were remarkably affordable, and were an inexpensive way to achieve transportation goals. In terms of economic returns, the limited data available suggests Complete Streets projects were related to broader economic gains like increased employment and higher property values.

These findings are based on data collected directly by local transportation and economic development agencies as reported to Smart Growth America’s National Complete Streets Coalition. The Coalition surveyed Complete Streets projects from across the country, and found 37 with transportation and/or economic data available from both before and after the project.

Safer Streets, Stronger Economies analyzes that data and explores the outcomes communities get for their investments in Complete Streets. In this tight budget climate, transportation staff and elected leaders want to get the most out of every dollar. This research shows Complete Streets projects can help them do just that.

OpenStreetCab: Exploiting Taxi Mobility Patterns in New York City to Reduce Commuter Costs

March 29, 2015 Comments off

OpenStreetCab: Exploiting Taxi Mobility Patterns in New York City to Reduce Commuter Costs
Source: arXiv.org

The rise of Uber as the global alternative taxi operator has attracted a lot of interest recently. Aside from the media headlines which discuss the new phenomenon, e.g. on how it has disrupted the traditional transportation industry, policy makers, economists, citizens and scientists have engaged in a discussion that is centred around the means to integrate the new generation of the sharing economy services in urban ecosystems. In this work, we aim to shed new light on the discussion, by taking advantage of a publicly available longitudinal dataset that describes the mobility of yellow taxis in New York City. In addition to movement, this data contains information on the fares paid by the taxi customers for each trip. As a result we are given the opportunity to provide a first head to head comparison between the iconic yellow taxi and its modern competitor, Uber, in one of the world’s largest metropolitan centres. We identify situations when Uber X, the cheapest version of the Uber taxi service, tends to be more expensive than yellow taxis for the same journey. We also demonstrate how Uber’s economic model effectively takes advantage of well known patterns in human movement. Finally, we take our analysis a step further by proposing a new mobile application that compares taxi prices in the city to facilitate traveller’s taxi choices, hoping to ultimately to lead to a reduction of commuter costs. Our study provides a case on how big datasets that become public can improve urban services for consumers by offering the opportunity for transparency in economic sectors that lack up to date regulations.

Mitigating Reptile Road Mortality: Fence Failures Compromise Ecopassage Effectiveness

March 27, 2015 Comments off

Mitigating Reptile Road Mortality: Fence Failures Compromise Ecopassage Effectiveness
Source: PLoS ONE

Roadways pose serious threats to animal populations. The installation of roadway mitigation measures is becoming increasingly common, yet studies that rigorously evaluate the effectiveness of these conservation tools remain rare. A highway expansion project in Ontario, Canada included exclusion fencing and ecopassages as mitigation measures designed to offset detrimental effects to one of the most imperial groups of vertebrates, reptiles. Taking a multispecies approach, we used a Before-After-Control-Impact study design to compare reptile abundance on the highway before and after mitigation at an Impact site and a Control site from 1 May to 31 August in 2012 and 2013. During this time, radio telemetry, wildlife cameras, and an automated PIT-tag reading system were used to monitor reptile movements and use of ecopassages. Additionally, a willingness to utilize experiment was conducted to quantify turtle behavioral responses to ecopassages. We found no difference in abundance of turtles on the road between the un-mitigated and mitigated highways, and an increase in the percentage of both snakes and turtles detected dead on the road post-mitigation, suggesting that the fencing was not effective. Although ecopassages were used by reptiles, the number of crossings through ecopassages was lower than road-surface crossings. Furthermore, turtle willingness to use ecopassages was lower than that reported in previous arena studies, suggesting that effectiveness of ecopassages may be compromised when alternative crossing options are available (e.g., through holes in exclusion structures). Our rigorous evaluation of reptile roadway mitigation demonstrated that when exclusion structures fail, the effectiveness of population connectivity structures is compromised. Our project emphasizes the need to design mitigation measures with the biology and behavior of the target species in mind, to implement mitigation designs in a rigorous fashion, and quantitatively evaluate road mitigation to ensure allow for adaptive management and optimization of these increasingly important conservation tools.

See: Mitigating reptile road mortality

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