Safety

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...

Comparative analysis of pedestrian injuries using police, emergency department, and death certificate data sources in North Carolina, US, 2007–2012

Sandt, LS
Proescholdbell, S
Evenson, K
Robinson, W
Rodriguez, D
Harmon, K
Marshall, S
2020
Pedestrian safety programs are needed to address the rising incidence of pedestrian fatalities. Unfortunately, most communities lack comprehensive information on the circumstances of pedestrian crashes and resulting injuries that could help guide decision-making for prevention program development and implementation. This study aimed to evaluate how three commonly available data sources (police-reported pedestrian crashes, emergency department [ED] visits, and death certificates) define and capture pedestrian injury data, and to compare the distribution of pedestrian injuries and fatalities...

Bicycle safety in Bogotá: A seven-year analysis of bicyclists’ collisions and fatalities

Carvajal, G
Sarmiento, OL
Medaglia, A
Cabrales, S
Rodríguez, D
Quintsberg, A
Lopez, S
2020
Road safety research in low- and middle-income countries is limited, even though ninety percent of global road traffic fatalities are concentrated in these locations. In Colombia, road traffic injuries are the second leading source of mortality by external causes and constitute a significant public health concern in the city of Bogotá. Bogotá is among the top 10 most bike-friendly cities in the world. However, bicyclists are one of the most vulnerable road-users in the city. Therefore, assessing the pattern of mortality and understanding the variables affecting the outcome of bicyclists’...

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...

Greenness and Excess Deaths from Heat in 323 Latin American Cities: Do Associations Vary According to Climate Zone or Green Space Configuration?

Schinasi, LH
Bakhtsiyarava, M
Sánchez, BN
Kephart, JL
Ju, Y
Arunachalam, S
Gouveia, N
Caiaffa, WT
O'Neill, MS
Dronova, I
Roux, AV Diez
Rodriguez, D
2023
Green vegetation may protect against heat-related death by improving thermal comfort. Few studies have investigated associations of green vegetation with heat-related mortality in Latin America or whether associations are modified by the spatial configuration of green vegetation. We used data from 323 Latin American cities and meta-regression models to estimate associations between city-level greenness, quantified using population-weighted normalized difference vegetation index values and modeled as three-level categorical terms, and excess deaths from heat (heat excess death fractions [heat...

Microsimulation Approach to Investigate the Impact of Incorrect Automated Pedestrian Detection on the Operation of Signalized Intersections

Gavric, S
Erdagi, IG
Rodriguez, D
Stevanovic, A
2024
Numerous studies have assessed video detection systems, but automated pedestrian video detection systems (APVDS) have not received as much attention. Although some researchers have evaluated the accuracy of APVDS, none quantified the consequential effects that false or missed pedestrian calls have on critical vehicular and pedestrian performance metrics. To address this gap, this study introduces a microsimulation-based approach to analyze the impact of missed and false pedestrian calls on signalized intersection operation. This method employs simulation inputs that mimic various detection...

A Comparison of Heat Effects on Road Injury Frequency Between Active Travelers and Motorized Transportation Users in Six Tropical and Subtropical Cities in Taiwan

Hsu, CK
Rodriguez, DA
2024
Road traffic injuries (RTIs) pose significant public health threats, particularly for vulnerable road users such as pedestrians and cyclists. While recent studies have revealed adverse impacts of heat exposure on RTI frequency among motorized road users, a research gap persists in understanding these impacts on non-motorized road users, especially in tropical regions where their vulnerability can be heightened due to differential thermal exposure, adaptive capacity, and biological sensitivity. In this study, we compared associations between high temperatures and RTIs across four different...

Planning and Accommodating the Micromobility Revolution and Its Impact on Public Health

Quistberg, Alex
Rodriguez, Daniel
2024

Micromobility has grown immensely over the past decade, encompassing both public shared systems and private ownership, and, as Burford et al. have found, a surge in user injuries and deaths has accompanied the growth. Micromobility refers to the use of small vehicles, such as bicycles and scooters, that are either human powered or electric. These vehicles are ideal for short trips—although electric-powered micromobility has expanded the potential distance range.