Safety

Effect of a Community-Based Pedestrian Injury Prevention Program on Driver Yielding Behavior at Marked Crosswalks

Sandt, LS
Marshall, S
Rodriguez, D
Evenson, K
Ennett, ST
Robinson, W
2016
Few studies have comprehensively evaluated the effectiveness of multi-faceted interventions intended to improve pedestrian safety. “Watch for Me NC” is a multi-faceted, community-based pedestrian safety program that includes widespread media and public engagement in combination with enhanced law enforcement activities (i.e., police outreach and targeted pedestrian safety operations conducted at marked crosswalks) and low-cost engineering improvements at selected crossings. The purpose of this study was to estimate the effect of the law enforcement and engineering improvement components of the...

A Vehicle Collision Model for Platoon Controller Development

Tongue, Benson H.
Packard, Andrew
Harriman, Douglas
1997

This is the final report of the research program “Compatibility of Vehicles Within a Platoon (MOU-156).” This research area is continuing under a different, contract and thus, although the work presented herein is complete unto itself, the overall research goals laid out at the beginning of the program will not be attained until the conclusion of the entire related research effort.The material presented in this report provides a description of a simple dynamical model that can be used for determining the physical interaction of vehicles in a collision scenario. Such a model is of use in...

The I-880 Field Experiment: Effectiveness Of Incident Detection Using Cellular Phones

Skabardonis, Alexander
Chira-chavala, Ted
Rydzewski, Daniel
1996

This report describes the evaluation of the effectiveness and adequacy of cellular phones for incident detection as an alternative to infrastructure-based surveillance systems. The analysis was part of the I-880 field experiment using the California Highway Patrol's (CHP) Computer Aided Dispatch (CAD) incident database. Cellular phones have the highest detection rate among the examined detection sources. Results from the study, however, indicate that incidents reported by cellular phones show greater incident durations than similar incidents reported by the CHP or the Freeway Service...

Finding and Analyzing True Effect of Non-recurrent Congestion on Mobility and Safety

Varaiya, Pravin
2007

This report summarizes empirical research about the causes and impact of non-recurrent congestion. A method is presented to divide the total congestion delay in a freeway section into six components: the delay caused by incidents, special events, lane closures, and adverse weather; the potential reduction in delay at bottlenecks that ideal ramp metering can achieve; and the remaining delay, due mainly to excess demand. The method can be applied to any site with minimum calibration, but it requires data about traffic volume and speed; the time and location of incidents, special events and...

Spacing And Capacity Evaluations For Different Ahs Concepts

Kanaris, Alexander
Ioannou, Petros
Ho, Fu-sheng
1996

In this study, the authors consider a family of six Automated Highway Systems (AHS) operational concepts. For each concept, the minimum inter- vehicle spacing that could be used for collision-free vehicle following, under different road conditions, is calculated. For architectures involving platoons, the authors also use the alternative constraint of bounded energy collisions to calculate the spacing that can be applied if collisions at a limited relative velocity were allowed. In every case, the minimum spacing in turn, is used to calculate the maximum possible capacity that could be...

Organizing For Its: Computer Integrated Transportation Phase 2: Results For Emergency Operations

Lo, H.
Rybinski, H.
1996

This paper extends research on Computer Integrated Transportation (CIT) to emergency operations (EOs). The objectives of the study are to examine EOs in California, identify their role in gathering and using traffic incident information, establish the basis of coordination between EOs and TMCs, identify Intelligent Transportation Systems (ITS) services and technologies that may be beneficial to their operations, and finally compare and contrast similarities and differences between the California emergency operations and the emerging ITS National Architecture. This report covers the...

Evaluation of Coordinated Ramp Metering (CRM) Systems in California

Mauch, Michael
Skabardonis, Alexander
2021

Freeway on-ramp metering (RM) has been extensively used as a traffic control strategy to regulate the entry of the on-ramp vehicles to prevent congestion at the freeway merging areas and preserve the freeway capacity. Benefits of RM include improved freeway travel times, improved travel time reliability, and accident reductions. Fixed-rate ramp metering strategies are based on historical data and implemented by time of day. Traffic responsive RM strategies are based on real time freeway traffic data provided by loop detectors at the vicinity of the on-ramp. Coordinated RM determine the...

Low Speed Collison Dynamics And Control: Year One Report

Tongue, Benson H.
Moon, Ahrie
1995

This report discusses the issues investigated during the first phase of a project which focuses on the development of a simulation program which will allow the study of platoon dynamics in both nominal and emergency scenarios. Preliminary issues include collision detection between the vehicles within the platoon and determining the platoon's post-crash behavior. A two-dimensional vehicle has been developed to addresses these issues. The overall simulation program includes individual modules that supply control input force, aerodynamic drag force, and road-tire interaction forces....

Evaluation Of The Freeway Service Patrol ( F S P ) In Los Angeles

Skabardonis, Alexander
Petty, Karl
Varaiya, Pravin
Bertini, Robert
1998

This report presents the results of a study designed to evaluate the effectiveness of the freeway service patrols (FSP) on a section of I-10 in Los Angeles. An evaluation methodology was used to estimate incident delays based on loop detector data and probe vehicles, and derive estimates of savings in performance measures in the absence of data for before FSP conditions. The estimated benefit cost ratios based on delay and fuel savings for a range of typical reductions in incident durations indicate that FSP produces significant benefits at the test site. Additional benefits include...

Urban Landscape and Street-design Factors Associated with Road-Traffic Mortality in Latin America between 2010 and 2016 (SALURBAL): An Ecological Study

Quistberg, D
Hessel, P
Rodriguez, DA
Sarmiento, OL
Bilal, U
Caiaffa, WT
Miranda, J
de Pina, M
Hernandez-Vazquez, A
Roux, AV Diez
2022
Road-traffic injuries are a key cause of death and disability in low-income and middle-income countries, but the effect of city characteristics on road-traffic mortality is unknown in these countries. The aim of this study was to determine associations between city-level built environment factors and road-traffic mortality in large Latin American cities. We selected cities from Argentina, Brazil, Chile, Colombia, Costa Rica, El Salvador, Guatemala, Mexico, Panama, and Peru; cities included in the analysis had a population of at least 100 000 people. We extracted data for road-traffic deaths...