Speed Bumps
Speed Bump Dimensions: Width, Length & Height
Cojo
May 7, 2026
6 min read
Speed bumps trip buyers up because the word "width" gets used two different ways. Manufacturers and the ITE Traffic Calming Manual define width as the horizontal measurement perpendicular to travel — how far across the lane the bump extends, typically 8 to 24 feet. Buyers often use "width" to mean the horizontal measurement in the direction of travel — how far across the bump a tire rolls. That second measurement is correctly called length and runs 1 to 3 feet for parking-lot bumps. We're using the ITE convention here.
Below: width vs length disambiguated, standard section sizes, and how to pair sections to cover full lane width.
Two horizontal measurements describe a speed bump:
When buyers ask "how wide is a speed bump," they usually mean length. When manufacturers list "10-foot section width," they mean the lane-span dimension.
Throughout this guide:
Most other Cojo articles match this convention. The Federal Highway Administration Traffic Calming ePrimer (safety.fhwa.dot.gov) uses the same convention.
| Device | Length (Direction of Travel) | Target Speed |
|---|---|---|
| Light-duty residential bump | 1 to 1.5 feet | 5 mph |
| Standard parking-lot bump | 1.5 to 3 feet | 5 mph |
| Heavy-duty commercial bump | 2 to 3 feet | 5 mph |
| Speed hump | 12 to 14 feet | 15 to 20 mph |
| Speed table | 22 feet | 25 mph |
For deeper detail on the bump-vs-hump distinction, see speed bump vs speed hump.
ITE Parking Generation Manual references typical commercial drive-aisle widths in the US:
The bump must span full lane width to prevent steering-around. A 22-foot two-way drive aisle needs 22 feet of bump; leaving a 4-foot gap defeats the purpose.
Manufacturers sell modular rubber and plastic speed bumps in fixed lane-span sections that buyers link end-to-end:
| Section Size | Typical Use | Connector |
|---|---|---|
| 2-foot mid-section | Trim piece for odd lane widths | Required |
| 4-foot section | Driveways, narrow drive lanes | Optional |
| 6-foot section | Single-lane parking aisles | Optional |
| 10-foot section | Two-way drive aisles | Required for end caps |
| 12-foot section | Wider drive lanes | Required for end caps |
Worked examples for common lane widths:
| Lane Width | Section Pairing |
|---|---|
| 12 feet (single-lane) | One 12-foot section + 2 end caps |
| 14 feet | One 12-foot + one 2-foot mid-section + 2 end caps |
| 22 feet (two-way) | Two 10-foot + one 2-foot mid-section + 2 end caps |
| 24 feet | Two 12-foot + 2 end caps |
| 26 feet | Two 12-foot + one 2-foot mid-section + 2 end caps |
| 30 feet (wide entrance) | Two 12-foot + one 6-foot + 2 end caps |
For dimensional spec on all three measurements (height, length, width), see speed bump dimensions. For height-only detail, see how tall are speed bumps.
Three options for non-standard lane widths:
Cojo's commercial estimator measures drive-aisle width during the site survey and recommends section pairings that cover the full lane without gaps.
ITE Traffic Calming Manual chapter 3 references "steering avoidance" as the dominant failure mode when bump width does not span the lane. Drivers steer around any gap larger than 12 to 18 inches because passenger vehicles can roll through that gap without slowing.
The result of partial coverage:
Partial coverage is the most common installation error Cojo sees in retrofit work.
On a 14,000-square-foot Salem retail center we restriped in March 2026, the previous contractor had installed four 6-foot speed bumps centered in 22-foot two-way drive aisles, leaving 8 feet of clear lane on each side of every bump. Drivers had been steering around for two years. We replaced all four with full-lane-coverage section pairings (two 10-foot sections plus a 2-foot mid-section per bump). Speed observations dropped from 18 mph average to 8 mph within a week.
A 12-foot single-lane drive aisle uses 12 feet of bump. A 22-foot two-way drive aisle uses 22 feet. Per-foot material cost (per speed bump cost per foot) ranges from $20 to $60 per foot for rubber and $30 to $200+ installed for asphalt.
Property managers comparing material costs across multiple sites should see our Speed Bumps in Portland Metro commercial guide for regional drive-aisle norms. For paving and marking spec context, see our concrete vs asphalt striping guide.
Speed bump width depends on lane geometry at your specific site. Get a custom quote and Cojo's estimator will measure your drive aisles and recommend section pairings that cover the full lane without gaps.
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