Pedestrians are legitimate users of the transportation system and they should, therefore, be able to use the system safely. Pedestrian needs in crossing streets should be identified, and appropriate solutions should be selected to improve pedestrian safety and access. Deciding where to mark crosswalks is only one consideration in meeting that objective. This study involved an analysis of 5 years of pedestrian crashes at 1,000 marked crosswalks and 1,000 matched unmarked comparison sites. None of the sites in this study had a traffic signal or stop sign on the approaches. Detailed data were collected on traffic volume, pedestrian exposure, number of lanes, type of median, speed limit, and other site variables. Poisson and negative binomial regressive models were used. Study results revealed that on two-lane roads the presence of a marked crosswalk alone at an uncontrolled location was associated with no difference in pedestrian crash rate, compared with an unmarked crosswalk. Further, on multilane roads with traffic volumes above about 12,000 vehicles per day, having a marked crosswalk was associated with a higher pedestrian crash rate (after controlling for other site factors) compared with an unmarked crosswalk. Raised medians provided significantly lower pedestrian crash rates on multilane roads, compared with roads without a raised median. Older pedestrians had crashes that were high relative to their crossing exposure. More substantial improvements were recommended to provide for safer pedestrian crossings, including adding traffic signals (with pedestrian signals) when warranted, providing raised medians, and implementing speed-reducing measures.

Each year many bicyclists are injured or killed in intersection-related crashes with motor vehicles. The objective of this study was to develop a macrolevel bicycle intersection safety index (Bike ISI) that would allow engineers, planners, and other practitioners to use known intersection characteristics to prioritize intersection approaches with respect to bicycle safety proactively. Using variables that indicate a higher probability of risk for bicyclists, the Bike ISI identifies which intersection approaches have the highest priority for bicycle safety improvements within a particular jurisdiction. Using video data and online ratings surveys, this study obtained data on avoidance maneuvers and safety ratings at 67 intersection approaches and developed a Bike ISI model that incorporated both measures of safety. The Bike ISI uses data on the traffic volume, the number of lanes, the speed limit, the presence of a bike lane, the presence of parking, and the presence of traffic control to give a rating for an intersection approach according to a six-point scale. Using the Bike ISI, practitioners have the ability to evaluate each approach at all intersections in their jurisdictions or at a select group of intersections. Once safety index values are assigned to each site, the practitioner can then select the sites with the highest index values and conduct more detailed reviews of those sites to determine whether any treatments are needed to improve the safety of the intersection.

“Road diets” are often conversions of four-lane undivided roads into three lanes (two through lanes plus a center turn lane). The fourth lane may be converted to bicycle lanes, sidewalks, or on-street parking. Road diets are sometimes implemented with the objective of reducing vehicle speeds as well as the number of motor vehicle crashes and injuries. A study was conducted to investigate the actual effects of road diets on motor vehicle crashes and injuries. Twelve road diets and 25 comparison sites in California and Washington cities were analyzed. Crash data were obtained for these road diet (2,068 crashes) and comparison sites (8,556 crashes). A “before” and “after” analysis using a “yoked comparison” study design found that the percent of road diet crashes occurring during the “after” period was about 6% lower than that of the matched comparison sites. However, a separate analysis in which a negative binomial model was used to control for possible differential changes in average daily traffic, study period, and other factors indicated no significant treatment effect. Crash severity was virtually the same at road diets and comparison sites. There were some differences in crash type distributions between road diets and comparison sites, but not between the “before” and “after” periods. Conversion to a road diet should be made on a case-by-case basis in which traffic flow, vehicle capacity, and safety are all considered. It is also recommended that the effects of road diets be further evaluated under a variety of traffic and roadway conditions.

This paper documents a study performed to develop a level-of-service (LOS) model that accurately represents pedestrians’ perceptions of crossings at signalized intersections. This model incorporates perceived safety and comfort (i.e., perceived exposure and conflicts) and operations (i.e., delay and signalization). Data for the model were obtained from an innovative Walk for Science field data collection event and video simulations. The data consist of ( a) participants’ perceptions of safety, comfort, and operations as they walk through selected signalized intersections and ( b) the design and operational characteristics of these intersections. The resulting model provides a measure of the pedestrian's perspective on how well an intersection's geometric and operational characteristics meets his or her needs. The pedestrian LOS model for intersections described in this paper is based on Pearson correlation analyses and stepwise regression modeling of approximately 800 combined real-time perceptions (observations) from pedestrians walking a course through signalized intersections in a typical U.S. metropolitan area. The resulting general model for the pedestrian LOS at intersections is highly reliable, has a high correlation coefficient ( R2 = .73) with the average observations, and is transferable to the majority of metropolitan areas in the United States. Primary factors in the pedestrian LOS model for intersections include right-turn-on-red volumes for the street being crossed, permissive left turns from the street parallel to the crosswalk motor vehicle volume on the street being crossed, midblock 85th percentile speed of the vehicles on the street being crossed, number of lanes being crossed, pedestrian's delay, and presence or absence of right-turn channelization islands.

Also known as road humps, undulations, or "sleeping policemen,"