Description:

• a series of narrowings or curb extensions that alternate from one side of the street to the other forming S-shaped curves
• also called deviations, serpentines, reversing curves, twists, and staggerings

Applications:

• appropriate for midblock locations only
• most effective with equivalent volumes on both approaches
• typically, is a series of at least three curb extensions
• can use on-street parking to create chicane

	Design/Installation Issues: unless well-designed, chicanes may still permit speeding by drivers cutting straight paths across the center line European manuals recommend shifts in alignment of at least one lane width, deflection angles of at least 45 degrees, and center islands to prevent drivers from taking a straight "racing line" through the feature

Potential Impacts:

• no effect on access
• limited data available on their effect on speed, volume, and collisions
• street sweeping may need to be done manually
• can impact parking and driveway access
• provides opportunity for landscaping

Emergency Response Issues:

• limited data available on their effect on delay to emergency response
• emergency response typically prefer two-lane chicanes to speed humps

Typical Cost:

• reported costs range between $5,000 and $15,000 (1997 dollars)

1627 I ("Eye") Street, NW, Suite 600
Washington, DC
20005-3538 USA
Phone: 202-785-0060
Fax: 202-785-0609
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SPEED HUMP | SPEED TABLE | RAISED INTERSECTION | CLOSURE | NEIGHBORHOOD TRAFFIC CIRCLE | CHICANE | CHOKER | CENTER ISLAND NARROWING