Speed Bumps
Speed Bump Spacing: How Far Apart Should Speed Bumps Be?
Cojo
May 7, 2026
6 min read
Parking-lot speed bumps belong 100 to 200 feet apart, per the ITE Traffic Calming Manual — 150 feet is the spec we use most often on commercial drive aisles. Residential street speed humps run 150 to 300 feet apart, per ITE and the FHWA Traffic Calming ePrimer. The reason both ranges exist: a driver shouldn't have enough room to accelerate back to pre-bump speed before hitting the next bump. Otherwise the bumps don't slow anyone down on average.
Below: the acceleration-window math, ITE spacing recommendations by site type, and how spacing plays against bump length and target speed.
Three reasons drive the spacing recommendation:
The 100 to 200-foot parking-lot range and 150 to 300-foot residential-street range balance these three drivers.
| Site Type | Recommended Spacing | Source |
|---|---|---|
| Parking lot drive aisle | 100 to 200 feet | ITE Traffic Calming Manual chapter 3 |
| Residential street | 150 to 300 feet | ITE Traffic Calming Manual chapter 3 |
| Collector street | 250 to 500 feet | FHWA Traffic Calming ePrimer |
| School zone | 100 to 250 feet | Oregon DOT school-zone guidance |
| Drive-thru lane | 80 to 150 feet | ITE Parking Generation Manual |
| Apartment complex private street | 120 to 250 feet | ITE Traffic Calming Manual |
Spacing should match bump length and target speed:
| Bump Type | Length | Target Speed | Recommended Spacing |
|---|---|---|---|
| Parking-lot speed bump | 1 to 3 feet | 5 mph | 100 to 200 feet |
| Residential speed hump | 12 to 14 feet | 15 to 20 mph | 150 to 300 feet |
| Speed table | 22 feet | 25 mph | 250 to 500 feet |
For deeper detail on the bump-vs-hump-vs-table family, see speed bump dimensions. For broader code context, see speed bump standards MUTCD.
Bumps closer than 100 feet on parking-lot drive aisles produce three problems:
Per Oregon city traffic-calming program references (Portland PBOT, Salem PW Chapter 79, Eugene EPP), 100 feet is the minimum acceptable spacing in residential settings, and 80 feet is the minimum in parking-lot contexts.
Bumps farther apart than 200 feet on parking-lot drive aisles produce a different failure:
ITE Traffic Calming Manual chapter 3 specifically warns against spacings above 300 feet for residential streets and above 200 feet for parking lots.
Three steps:
For broader traffic-calming strategy beyond bumps alone, see how to slow down parking lot traffic. For property managers comparing layouts across multiple sites, our Speed Bumps in Portland Metro commercial guide covers regional norms.
A typical 50,000-square-foot Salem retail center has roughly 1,000 linear feet of drive aisle in three corridors. Bump layout per ITE-spec spacing:
| Corridor | Length | Bumps | Spacing |
|---|---|---|---|
| Main entry to far row | 400 ft | 3 | 100 ft + 100 ft + 100 ft + 100 ft (last to exit) |
| Cross-aisle | 350 ft | 2 to 3 | 100 to 150 ft |
| Rear loading aisle | 250 ft | 1 to 2 | 100 to 250 ft |
Slight variations apply:
For marking-and-paint-cycle context, see commercial striping Portland.
Bump spacing depends on corridor length, target speed, and site context at your specific property. Get a custom quote and Cojo's estimator will measure your drive aisles, conduct a 75th-percentile speed observation, and recommend ITE-spec spacing before any bump goes in.
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