King Fahd University of Petroleum and Minerals Civil Engineering Department CE599-Seminar Traffic Calming Techniques By: Maen A. Abu Olba

Presentation Outline Definition. Definition. Main objectives. Main objectives. Main types. Main types. Design principles Design principles Practical example. Practical example. Conclusions and Recommendations Conclusions and Recommendations

What is Traffic Calming? Traffic calming is the combination of mainly physical measures that reduce the negative effects of motor vehicle use, alter driver behavior and improve conditions for non- motorized street users Traffic calming is the combination of mainly physical measures that reduce the negative effects of motor vehicle use, alter driver behavior and improve conditions for non- motorized street users

Objectives of Traffic Calming Achieving slow speeds and low volumes of motor vehicles. Achieving slow speeds and low volumes of motor vehicles. Reducing collision frequency and severity. Reducing collision frequency and severity. Increasing the safety and the perception of safety for non-motorized users of the street(s). Increasing the safety and the perception of safety for non-motorized users of the street(s). Reducing the need for police enforcement. Reducing the need for police enforcement. Reducing air pollution and noise associated with increased traffic speed and volume. Reducing air pollution and noise associated with increased traffic speed and volume.

Traffic Calming Techniques (Measures) Volume control measures: Volume control measures: are primarily used to address cut-through traffic problems by blocking certain movements, thereby diverting traffic to streets better able to handle it. are primarily used to address cut-through traffic problems by blocking certain movements, thereby diverting traffic to streets better able to handle it. Speed control measures: Speed control measures: are primarily used to reduce the speed. Two types: vertical deflection and horizontal deflection. are primarily used to reduce the speed. Two types: vertical deflection and horizontal deflection.

Volume control measures Full Closures: Full Closures:

Half Closures: Half Closures:

Speed Control Measures Vertical Deflection Speed Humps: Speed Humps:

b Speed tables: Speed tables:

Horizontal Deflection Traffic Circles Traffic Circles

Roundabouts: Roundabouts:

Design Principles Horizontal Curvature vs. Vehicle Speed Relation between horizontal curvature to operating speed is represented by the following formula : Relation between horizontal curvature to operating speed is represented by the following formula : R = V 2 / 15(e+f) For traffic calming purposes, R represents the maximum horizontal radius required to cause driver discomfort and reduce his speed. For traffic calming purposes, R represents the maximum horizontal radius required to cause driver discomfort and reduce his speed.

Vertical Curvature vs. Vehicle Speed Crossing speed is a function of the cross- sectional area. The greater the ratio of cross- sectional area to length, the lower the design speed. Crossing speed is a function of the cross- sectional area. The greater the ratio of cross- sectional area to length, the lower the design speed.

Practical Examples U.S.A In North Ida Avenue project in Portland, (OR.), the first phase of the project involved 14-foot speed humps at three locations. In North Ida Avenue project in Portland, (OR.), the first phase of the project involved 14-foot speed humps at three locations. These installations were followed by the narrowing of travel lanes to make room for bicycle lanes. These installations were followed by the narrowing of travel lanes to make room for bicycle lanes.

Daily Traffic Volumes Before and After Traffic Calming on N. Ida Avenue. (Portland, OR.)

Conclusions and recommendations The construction cost of different traffic calming measures varies based on the material used in the construction and the use of landscaping. The construction cost of different traffic calming measures varies based on the material used in the construction and the use of landscaping. The traffic calming measures must be designed to accommodate emergency vehicles. The traffic calming measures must be designed to accommodate emergency vehicles. Avoid placing traffic calming measures near hospitals and fire stations. Avoid placing traffic calming measures near hospitals and fire stations.

Traffic calming measures reduce speed, collision severity and crime. Traffic calming measures reduce speed, collision severity and crime. Traffic calming should be well marked and delineated Traffic calming should be well marked and delineated Adequate traffic singes must be installed in the area of traffic calming measures. Adequate traffic singes must be installed in the area of traffic calming measures. They are generally more self-enforcing than education and traditional enforcement efforts They are generally more self-enforcing than education and traditional enforcement efforts

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