The performance of drivers with physical limitations at T-intersections

The research examines the effect of restricted head and neck movement on driving performance as measured by decision time at T-intersections. The traffic safety and human factors literature was reviewed, and very little was found concerning drivers with physical limitations. T-intersections were selected for study because most accidents involving drivers with diminished capacities occur at intersections, and T-intersections are simpler than four-way intersections. A laboratory study was selected to provide better experimental control, safety and repeatability. A unique methodology was used that employed a fixed base driving simulator which incorporated the use of video recordings of intersections to provide a 180 degree field of view. Eighteen intersections were studied with various levels of traffic volume and sight distance. The 72 test subjects were between the ages of 30-50, or 60-80, and half in each age group had restricted range of movement of their neck. The task for the subjects was to depress the brake pedal, watch the video presentations of the T-intersections on three screens and indicate when it was safe to make a left turn by releasing the brake pedal. The decision time was a measure of driving performance. The study results confirmed the hypotheses that; 1. decision time increases with age, and age effects dominated the other factors which were studied, 2. decision time increases with age and level of impairment indicating that younger drivers are able to compensate for their impairments, but older drivers both with and without impairments are unable to make compensations in their driving performance, 3. traffic volume has a greater impact on decision time at intersections than sight distance, 4. skewed intersections are hazardous for drivers with neck impairments. Further laboratory and field studies are recommended to validate the study results and to examine the problem of skewed intersections

Planning of a Secondary Road Network for Low-Speed Vehicles in Small or Medium-Sized City: Using Google Earth

In response to the growing environmental concern, the use of low speed vehicles (LSVs) on public roadways is gradually increasing in recent years as a short-range alternative to fossil-fueled autos. Primarily designed for protected environments and gated communities, LSVs have a maximum speed limit of 25 mph and are not subjected to the same Federal Motor Vehicle Safety Standards required for regular passenger cars. This paper presents a comprehensive planning methodology for the development of a secondary low speed roadway network primarily intended for use by LSVs that can be applied to small or medium-sized cities with closely located activity spaces. Typically, small or medium sized cities have limited planning or construction resources, therefore the objective was to develop the low speed network based on the existing road system of the city, with minimal infrastructure modifications. The City’s Transportation Plan and public opinion on route preference were integrated with the road analysis tool of Google Earth to accomplish the network development process. Public involvement in the process through a survey provided valuable insight on users’ route choice behavior; whereas the roadway inventory by City’s Transportation Planning document and Google Earth helped to evaluate city’s actual transportation infrastructure and also helped to analyze the factors influencing LSV users’ route preference behavior. The developed low speed roadway network is expected to provide safe and efficient connectivity from neighborhood areas to major activity centers of the city by LSVs, while minimally affecting the safe operations of regular automobiles.KEYWORDS: Transportation infrastructure, Corvallis, Oregon, Secondary road network, Low speed vehicles (LSVs)This is the author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by the Transportation Research Board of the National Academies and can be found at: http://www.trb.org/Main/Blurbs/154702.aspx

Improved Collision Protection for Train Passengers Seated in Wheelchairs: Evaluation of Active and Passive Strategies

DTFR3-17-C-000041/ 693JJ622C000041The project evaluates wheeled mobility device (WhMD) securement and occupant restraint on passenger trains. Researchers tested three off-the-shelf wheelchair securement systems in a train-to-train collision as a proof-of-concept to mitigate the effects of second impact velocity. The tests evaluated the performance of the securement devices regarding human injury, compartmentalization, structural integrity, and attachment. The team conducted a full-scale train-to-train impact test at the Transportation Technology Center in Pueblo, Colorado, on August 11, 2022. Three WhMD occupant protection experiments were installed in the M1 passenger cars behind the Crash Energy Management (CEM) locomotive in the moving consist. These experiments included different types of wheelchairs, restraint systems, and Hybrid III 50th percentile male (H3-50M) anthropomorphic test devices (ATDs) equipped with instrumentation to measure force, moment, acceleration, and displacement data. All the backboards, wheelchair securement, and occupant restraint systems used in the experiments maintained their structural integrity and remained attached to the carbodies during the tests. The injury values measured by the H3-50Ms were well below the limits and met the performance requirements specified in the APTA seat and table standards

Impacts of Low-Speed Vehicles on Transportation Infrastructure and Safety

There are increasing numbers of low-speed electric vehicles (LSVs) on public roadways. These vehicles are designed to be used within protected environments and on roadways with a maximum posted speed of 25 mph. Currently these vehicles are not subject to the same federal requirements for occupant protection as passenger cars. This research project investigated safety standards, operating regulations, and LSV manufacturer materials from sources around the world. The purpose of the research was to determine positive and negative impacts that LSVs, including Neighborhood Electric Vehicles (NEVs) and Medium Speed Electric Vehicles (MSEVs), are likely to have for the Oregon Department of Transportation (ODOT) and Oregon communities, and whether adjustments in current state regulations are needed to ensure that LSVs do not negatively impact road safety and traffic operations, or expose the LSV operators to undue risk. The U.S. and Canadian federal motor vehicle safety agencies have harmonized their regulations and stipulated the maximum operating speed of these vehicles, however state and local roadway authorities have regulated the maximum speed of roadways and intersection characteristics on which these vehicles can operate. The significant recommendations of this research are: (i)The State of Oregon regulations for LSVs should be amended such that LSVs are limited to public roadways with a maximum operating speed of 25 mph, and they are restricted to crossing higher speed roadways at four-way Stop or traffic controlled intersections, (ii) local transportation authorities should develop parallel or secondary low-speed transportation networks that connect residential neighborhoods with major activity center

Investigation of Wheeled Mobility Device Orientation and Movement on Streetcars and Light Rail Vehicles during Normal and Emergency Braking

Wheeled mobility devices have been accessing public transit vehicles for decades, and most new rail transit systems are accessible. This has increased ridership by people with disabilities. Side-facing orientation on rail transit vehicles often is considered an option to increase capacity for wheeled mobility devices. This paper reports findings of a study of vehicle dynamics and wheeled mobility device orientation on rail transit vehicles. The study used acceleration data and field observations to evaluate wheeled mobility devices in longitudinal and side-facing orientations on streetcar and light rail vehicles. Results from the study include recommendations for longitudinal-oriented areas for wheeled mobility devices as well as additional public outreach on best practices for passengers who use wheeled mobility devices on rail transit vehicles

Programming Safety Improvements on Pavement Resurfacing, Restoration, and Rehabilitation Projects

As part of the project planning process, highway agencies must allocate limited funding to a substantial list of projects that exceeds available resources. For preservation projects, a key component of this decision is to determine which projects receive safety improvements and which are pave only. Traditionally, this decision has been made project by project, with the possible result of a selection that does not maximize safety benefits. This paper takes a case study approach and applies a new tool developed in NCHRP Report 486, the Resurfacing Safety Resource Allocation Program (RSRAP), to a subset of the Oregon Department of Transportation\u27s (DOT\u27s) highway network. The RSRAP tool maximizes safety improvements for a given set of projects and budget. Thirty-three projects scheduled to receive a new road surface were selected and analyzed with RSRAP. These projects were subdivided into smaller sites to meet the assumptions of RSRAP. Road geometry, traffic volumes, and crash history for each site were collected and input into the program. The type and cost of the safety improvements output by RSRAP were compared with those selected by Oregon DOT. This research determined that RSRAP, which selected more projects for safety improvements than did Oregon DOT, is a tool that could be used by the department to select various safety improvements on pavement preservation projects. It was also determined that the budget used by Oregon DOT was large enough that all cost-effective improvements could be made