Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 4 of 4
Full-Text Articles in Engineering
Assessing The Impact Of Three Intersection Treatments In A Bicycling Simulator, Logan Scott-Deeter, David Hurwitz, Brendan Russo, Edward Smaglik, Sirisha Kothuri
Assessing The Impact Of Three Intersection Treatments In A Bicycling Simulator, Logan Scott-Deeter, David Hurwitz, Brendan Russo, Edward Smaglik, Sirisha Kothuri
Civil and Environmental Engineering Faculty Publications and Presentations
Bicyclist safety at urban intersections is a critical element for encouraging an increase in bicycle commuting. With cyclist injury and fatality rates rising due to collisions with vehicles at signalized intersections, increasing the safety of riders continues to be an important consideration when promoting this mode of transportation. Previous research has addressed crash causality and helped to develop several roadway treatments to improve bicyclist safety, but little has been done to compare and contrast the benefits of the various treatment types. This bicycling simulator study examined the impacts of three different intersection treatments (i.e., bike box, mixing zone, and bicycle …
Evaluation Of Posted Speed Limits Reductions On Urban Roads With A High Percentage Of Cyclists, Jaclyn S. Schaefer, Miguel Figliozzi, Avinash Unnikrishnan
Evaluation Of Posted Speed Limits Reductions On Urban Roads With A High Percentage Of Cyclists, Jaclyn S. Schaefer, Miguel Figliozzi, Avinash Unnikrishnan
Civil and Environmental Engineering Faculty Publications and Presentations
This paper presents a before and after analysis of the impact of posted speed limit (PSL) changes on passenger car (FHWA class two vehicles) speeds in Portland, OR. The study focuses on urban roads, comparing sites that underwent a PSL 5-mph reduction (treatment sites) and sites where the PSL did not change (control sites). Sites with a high percentage of and priority for cyclists (neighborhood greenways) and sites with a more standard traffic composition were compared. Differences in speed characteristics such as mean and 85th percentile speeds, the speed variance, and the proportion of vehicles exceeding a speed threshold (relative …
Evidence From Urban Roads Without Bicycle Lanes On The Impact Of Bicycle Traffic On Passenger Car Travel Speeds, Jaclyn S. Schaefer, Miguel A. Figliozzi, Avinash Unnikrishnan
Evidence From Urban Roads Without Bicycle Lanes On The Impact Of Bicycle Traffic On Passenger Car Travel Speeds, Jaclyn S. Schaefer, Miguel A. Figliozzi, Avinash Unnikrishnan
Civil and Environmental Engineering Faculty Publications and Presentations
A concern raised by some motorists in relation to the presence of bicycles on urban roads without bicycle lanes, discussed in part of the traffic literature, is that cyclists will slow down motorized vehicles and therefore create congestion. This research answers this question: do bicycles reduce passenger car travel speeds on urban roads without bicycle lanes? To answer this question, a detailed comparative analysis of the travel speeds of passenger car (class two vehicles) on lower volume urban roads without bicycle lanes is presented. Speed distributions, the mean, and the 50th and 85th percentile speeds for two scenarios were examined: …
A Level-Of-Service Model For Protected Bike Lanes, Nick Foster, Christopher Monsere, Jennifer Dill, Kelly Clifton
A Level-Of-Service Model For Protected Bike Lanes, Nick Foster, Christopher Monsere, Jennifer Dill, Kelly Clifton
Civil and Environmental Engineering Faculty Publications and Presentations
Several methods exist for quantifying the quality of service provided by a roadway from a bicyclist’s perspective; however, many of these models do not consider physically protected bike lanes and, of those that do, none is based on empirical data from the US. This is problematic as engineers, planners, and elected officials are increasingly looking to objective performance measures to help guide transportation project design and funding prioritization decisions. This paper addresses this gap by presenting a cumulative logistic model to predict user comfort on protected bike lanes developed from data collected during in-person video surveys. The surveys were conducted …