Speed tables are midblock traffic calming devices that raise the entire wheelbase of a vehicle to reduce its traffic speed. Speed tables are longer than speed humps and flat-topped, with a height of 3–3.5 inches and a length of 22 feet. Vehicle operating speeds for streets with speed tables range from 25–45 mph, depending on the spacing.1
Speed tables may be used on collector streets and/or transit and emergency response routes. Where applied, speed tables may be designed as raised midblock crossings, often in conjunction with curb extensions.
Where a speed table coincides with a crossing or crosswalk, it should be designed as a raised crosswalk.
“Speed Bumps,” Bureau of Traffic Management Traffic Manual (Portland: Portland Bureau of Transportation).
Adapted from the Urban Street Design Guide, published by Island Press.