Topic
Design speed
About: Design speed is a research topic. Over the lifetime, 697 publications have been published within this topic receiving 7562 citations.
Papers published on a yearly basis
1 / 2
Papers
Journal Article•
TL;DR: In this paper, the authors investigated the influence of traffic engineering factors on the variance of vehicle speeds in a traffic stream and quantified the relationship between speed variance and accident rates, and found that drivers tend to drive at increasing speeds as the roadway geometric characteristics improve, regardless of the posted speed limit.
Abstract: One of the major factors that should be considered in selecting the speed limit for a stretch of highway is safety. It is generally accepted that the level of safety depends on certain characteristics of the traffic stream and the geometric alignment of the highway. However, in many cases speed limits are posted without adequate consideration given to these characteristics. For example, an important traffic characteristic that influences safety is speed variance. Currently, little is known about the factors that affect the variance of vehicle speeds in a traffic stream. Presented in this paper are the results of a study that investigated the influence of different traffic engineering factors on speed variance and quantified the relationship between speed variance and accident rates. A major influence on speed variance is the difference between the design speed and the posted speed limit. It was determined that speed variance will approach minimum values if the posted speed limit is between 5 and 10 mph lower than the design speed. Outside this range, speed variance increases with an increasing difference between the design speed and the posted speed limit. It was also found that drivers tend to drive at increasing speeds as the roadway geometric characteristics improve, regardless of the posted speed limit, and that accident rates do not necessarily increase with an increase in average speed but do increase with an increase in speed variance.
295 citations
Journal Article•
TL;DR: In this article, the relationship between design speed and operating speed is examined through a survey of the practice and a thorough analysis of geometric, traffic, and speed conditions, and the basis for recent changes in speed definitions in the American Association of State Highway and Transportation Officials' (AASHTO's) "A Policy on Geometric Design of Highways and Streets" (Green Book) and the "Manual on Uniform Traffic Control Devices" (MUTCD).
Abstract: This report examines the relationship between design speed and operating speed through a survey of the practice and a thorough analysis of geometric, traffic, and speed conditions. The basis for recent changes in speed definitions in the American Association of State Highway and Transportation Officials' (AASHTO's) "A Policy on Geometric Design of Highways and Streets" (Green Book) and the "Manual on Uniform Traffic Control Devices" (MUTCD) are presented. Researchers should find the data (available on the accompanying CD-ROM) to be very useful in further exploring relationships between roadway factors and operating speed. The report will be of interest to designers and others interested in understanding the factors that affect drivers' speeds.
236 citations
1 Jan 2000
TL;DR: In this paper, several efforts were undertaken to predict operating speed for different conditions such as on horizontal, vertical, and combined curves; on tangent sections using alignment indices; on grades using TWOPAS model; and prior to or after a horizontal curve.
Abstract: Design consistency refers to the conformance of a highway's geometry to driver expectancy. Drivers make fewer errors in the vicinity of geometric features that conform to their expectations. A technique to evaluate the consistency of a design is to evaluate changes in operating speeds along an alignment. To use operating speed as a consistency tool requires the ability to accurately predict speeds as a function of the roadway geometry. In this research project, several efforts were undertaken to predict operating speed for different conditions such as on horizontal, vertical, and combined curves; on tangent sections using alignment indices; on grades using TWOPAS model; and prior to or after a horizontal curve. The findings from the different efforts were incorporated into a speed-profile model. The model can be used to evaluate the design consistency of the roadway or can be used to develop a speed profile for an alignment. The model considers both horizontal and vertical curvature and the acceleration or deceleration behavior as a vehicle moves from one feature to another.
223 citations
TL;DR: Age, gender, group size, and street width were found to significantly contribute to pedestrian speed in Jordan, and Pedestrians 21–30 years old were the fastest group of pedestrians and pedestrians over 65 yearsOld were the slowest.
194 citations
TL;DR: In this article, the authors report the results of a study of a cohort of cyclists to determine their speed and acceleration characteristics relative to gradient and other influencing factors in order to supply data for planners, designers and appraisers of cycle infrastructure schemes.
147 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2025 | 1 |
| 2024 | 3 |
| 2023 | 7 |
| 2022 | 11 |
| 2021 | 17 |
| 2020 | 24 |