01091646

Component

Raised crosswalks are now widely used in urban areas as a speed control measure or traffic calming solution and are believed to be influential to safely reduce traffic speed, especially in residential areas or school zones. The most conspicuous advantages of these flat top humps are to provide more improved visibility and safety for pedestrians of whom children, the elderly and the disabled are gravely important. On the other hand, some disadvantages such as increasing response time for emergency vehicles, noise pollution, maintenance costs and drainage problems adversely affect their function. Although there are many studies devoted to different aspects of raised crosswalks such as their markings and signings, no rigorous research has been conducted to model the influence of their dimensions on speed reduction in urban streets. The current paper is an attempt to study this influence in Qazvin, Iran where they have been extensively installed as a speed control measure. In order to model such an influence, the streets were hierarchically sorted and typical streets for every category were chosen to install raised crosswalks in important places such as the disabled institutes, schools, hospitals and highly populated areas. Afterwards, surveying the dimensions of the installed raised crosswalks, street time mean speed (Sa) and time mean speed on the raised crosswalks (Sc) were measured. Finally, applying statistical tests to measure the importance of the dimensional variables, a model based on the statistically important variables was calibrated where the dependent variable was the [(Sa-Sc)/Sa]. The form of the model was chosen according to literature findings and a forward stepwise regression method was used for the calibration. This model that accurately models the [(Sa-Sc)/Sa] ratio can be nationally used by designers, engineers and decision-makers to optimally design the dimensions of raised crosswalks and have an idea how much traveling speed will be reduced installing raised crosswalks before installation. However, because this research does not examine the aforesaid impacts rigorously, similar researches should be done to evaluate such dimensional variety influence on those impacts such as: noise pollution, drivers discomfort, maintenance costs and installation costs. Moreover, these relationship needs to be investigated by heuristic methods such as Neural Network models rather than conventional statistical methods.

01091711

English

15p

2007

3rd Urban Street Symposium: Uptown, Downtown, or Small Town: Designing Urban Streets That Work

CD-ROM

Figures (5) ; References (20) ; Tables (3)

Average travel speed; Crosswalks; Highway design; Highway traffic control; Size; Speed control; Streets; Traffic calming; Urban areas

Raised crosswalks

Design; Highways; Operations and Traffic Management; Planning and Forecasting; I21: Planning of Transport Infrastructure; I73: Traffic Control

TRIS, TRB

Mar 28 2008 12:36PM

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• A Model of Potential Capacity of Right Turn Movement at Signalized Intersections Under Mixed Traffic Conditions
• Analysis of Multifunctional Traffic Environments
• Applying Context Sensitive Techniques to Improve Design and Gain Stakeholder Support
• Benefits and Risks of Urban Roadside Landscape: Finding a Livable, Balanced Response
• Cross Section Width for Parallel Parking
• Design and Traffic Organization for Ultra-Wide Urban Street in China
• Designing Inside the Box - Strategies to Successfully Marry Smart Growth and Context-Sensitive Transportation Initiatives
• Designing Streets for Enhanced Transit Service: The Jerusalem Experience
• Driveway Design Practices, Issues, and Needs
• Estimating Running Time on Urban Street Segments
• Four-Lane to Three-Lane Conversions: An Update and a Case Study
• Geometric Design of Interchange in Urban City
• Improving Pedestrian Safety at Unsignalized Intersections
• Integrating Context Sensitive Solutions into University Transportation Education
• Involving the Public in Redesigning Urban Street Layouts in the UK
• Iowa's Experience with 2-Lane to 3-Lane Conversions
• Iowa's Experience with 4-Lane to 3-Lane Conversions
• Minnesota CSAH 42: A Case Study Illustrating Traffic Signal Removal as an Access Management Strategy
• Pedestrian Crossings Priority for Pedestrian Safety
• Recent Superstreet Implementation and Research
• Responding to the Challenges of Bicycle Crossings at Offset Intersections
• Retrofitting Urban Arterials into Complete Streets
• Review of Guidelines for Establishing School Speed Zones
• Safety Effect of the Skew Angle in Right Turn Maneuvers
• Separation Between Pedestrians and Bicyclists
• Shared-Use Streets – An Application of “Shared Space” to an American Small Town
• Should Direct Left-turns from Driveways be Replaced by Right-turns Followed by U-turns? The Safety and Operational Comparison in Florida
• Speed: How Can We Get What We Want?
• St. Louis Great Streets Initiative
• Study on the Relationship of Intersection Design and Safety of Urban Unsignalized Intersection in China
• Study on the Safety Relationship between Left-turn Gap Acceptance and Waiting Time
• Sustainable Urban Street Design and Assessment
• Synthesis of the Median U-Turn Intersection Treatment, Safety, and Operational Benefits
• Traffic Calming in Slovenia
• Urban Street Reconstruction with Cultural Consideration-Research and Case Studies
• Yielding Behaviour and Interaction at Bicycle Crossings