A speed hump is a raised parabolic section of pavement, typically 3 to 4 inches tall and 12 to 14 feet long in the direction of travel, used to slow vehicles to 15 to 20 mph on residential streets. Unlike a speed bump (1 to 3 feet long, slows to 5 mph), a speed hump's longer profile lets emergency vehicles cross at moderate speed without losing contact with the road. The Institute of Transportation Engineers (ITE) classifies humps as a vertical traffic-calming device for streets with 25 mph posted limits.
Key takeaways
- Speed humps are 12 to 14 ft long and 3 to 4 in tall; speed bumps are 1 to 3 ft long.
- Designed for 25 mph residential streets, not 5 mph parking lots.
- Reduce 85th-percentile speeds 20 to 30% per FHWA Traffic Calming ePrimer.
- Asphalt is the dominant material; "rubber speed humps" are usually misnamed bumps.
- Public-street installation requires a city petition and traffic study.
What is a speed hump and how is it different from a speed bump?
Speed humps and speed bumps are both vertical deflection devices, but the geometry is different on purpose. A speed bump is short and aggressive, designed to force drivers to crawl over it. A speed hump is long and gentler, designed to slow traffic without stopping it. The ITE Traffic Calming Manual (Chapter 3) defines a speed hump as "a raised area of the roadway pavement surface extending across the travel way, generally with a height of 3 to 4 inches and a length of 12 to 14 feet."
For property managers picking between the two, the rule of thumb is simple. Parking lots, drive-aisles, and private driveways take speed bumps. Public residential streets, school approaches, and through-streets in HOA communities take speed humps. The full comparison lives in our speed bump vs speed hump decision guide.
Why do streets need speed humps?
Speed-related crashes are the largest single contributor to fatal pedestrian collisions on local streets. The U.S. Department of Transportation's Federal Highway Administration reports that the risk of pedestrian death rises from roughly 10% at 23 mph to 75% at 50 mph (FHWA Pedestrian Safety). Cities install speed humps to compress that risk window. A 12-foot parabolic hump cuts 85th-percentile speeds from 35 to 25 mph in typical conditions, per ITE field studies cited in the Traffic Calming Manual.
In a March 2026 install on a Lake Oswego residential greenway, our crew placed three asphalt speed humps at 280-foot intervals along a 940-foot collector. Pre-install spot-speed data showed an 85th percentile of 33 mph; post-install survey three weeks later read 24 mph.
What types of speed humps are there?
Four cross-section profiles dominate the speed hump market. Each has tradeoffs in driver comfort, emergency-vehicle compatibility, and installation cost.
| Profile | Length | Target speed | Best for | Notes |
|---|---|---|---|---|
| Parabolic | 12 ft | 15 to 20 mph | Most residential streets | The ITE standard. Smooth ride for cars. |
| Flat-top | 22 ft | 20 to 25 mph | Bus routes, fire-access streets | Technically a "speed table" — see below. |
| Sinusoidal | 14 ft | 18 to 22 mph | Streets with cycle traffic | Easier on bikes than parabolic. |
| Modular rubber | 12 ft | 15 to 20 mph | Temporary or removable installs | Bolts to existing asphalt. |
What materials are used for speed humps?
Asphalt is the dominant material for permanent speed humps because the geometry favors paved-in profiles. A 12-foot parabolic shape requires custom screeding to maintain the smooth curve; precast rubber units long enough to qualify as humps are uncommon in the U.S. market. When a property manager asks for a "rubber speed hump," what they usually receive is a rubber speed bump (1 to 3 feet long), which is a different device.
For installations on streets that may need future removal or seasonal changes (snow-belt cities like Bend), modular rubber units in 12-foot lengths exist but cost more per linear foot than asphalt. Concrete speed humps are rare and typically reserved for industrial sites where chemical exposure makes asphalt impractical.
Where are speed humps used?
Speed humps work best on streets where the goal is consistent moderate-speed traffic, not full stops. Five common applications:
- Residential streets: The dominant application. Cities install humps on collector and local streets where neighborhood petitions trigger traffic-calming projects.
- School zones: Approach streets to elementary and middle schools, particularly within 600 feet of the building per Oregon DOT school-zone guidance.
- HOA neighborhoods: Private streets in planned communities, where the HOA board has authority to install without city approval (subject to ORS 94 governance rules).
- Park access roads: Low-speed roads through public parks where pedestrian traffic mixes with vehicles.
- Hospital and college campuses: Internal roads with fixed speed limits below 25 mph.
Drive-aisle parking lots are a poor fit; the lower target speed (5 to 10 mph) calls for a speed bump instead. Highways and arterials are also unsuitable; humps at posted speeds above 30 mph generate vehicle damage and rollover risk.
How are speed humps installed?
A typical asphalt speed hump install runs 4 to 6 hours per unit with a three-person crew, a paving roller, and traffic control. The crew layouts the hump centerline, mills the asphalt 1 inch on the approach and departure tapers (so the hump rises smoothly out of the existing surface), places hot-mix in lifts, screeds the parabolic profile by hand, and rollers the surface. After cure, the crew paints chevron markings and installs the W17-1 advance warning sign 100 to 200 feet upstream.
For the full procedure with code citations, see the how to install speed humps step-by-step guide.
How much do speed humps cost?
Industry Baseline Range
| Item | Range |
|---|---|
| Asphalt speed hump (installed, single unit) | $1,500 to $5,000 |
| Multi-unit install (3+ humps, same site) | $1,200 to $3,800 per unit |
| Modular rubber speed hump (installed) | $2,000 to $4,500 per unit |
| Removal | $1,500 to $3,000 per hump |
Current market reality
Speed hump pricing in 2026 sits at the high end of historical baselines because hot-mix asphalt prices rose roughly 18% over 2024 to 2025 (per RSMeans regional data), traffic-control labor remains tight in Oregon's I-5 corridor, and prevailing-wage requirements on city contracts push labor lines higher. For full breakdowns, see the speed hump cost guide.
Are speed humps effective?
Yes. The published research consensus is that well-designed speed humps reduce 85th-percentile speeds by 20 to 30% and total traffic volume by 15 to 20% on residential streets, per the ITE Traffic Calming Manual and the FHWA Traffic Calming ePrimer. Effectiveness depends on spacing (humps placed too far apart let drivers re-accelerate between them) and on profile execution (a hump steeper than the parabolic standard increases speeds at the apex as drivers brake harder before and accelerate after).
Frequently asked questions
How tall should a speed hump be? Standard speed hump height is 3 to 4 inches, per ITE Traffic Calming Manual Chapter 3. Heights below 3 inches lose effectiveness; heights above 4 inches risk vehicle undercarriage damage and emergency-vehicle delays.
How long is a speed hump? A speed hump is 12 to 14 feet long in the direction of travel. The parabolic profile means the highest point sits in the middle, with the leading and trailing edges flush with the existing pavement.
Do speed humps damage cars? At posted speeds (15 to 20 mph), a properly built parabolic speed hump does not damage cars. The long profile lets the suspension articulate smoothly. Damage occurs when drivers cross at high speed (above 25 mph), when the hump exceeds 4 inches in height, or when the leading edge is too steep.
Can fire trucks cross speed humps? Yes, but with a delay. Fire apparatus typically slow to 10 to 12 mph at a 12-foot hump. For streets where emergency response time is critical, speed cushions (with wheel-track gaps) or speed tables (longer flat-top profile) are the preferred device.
How do I get a speed hump on my street? On a public street, file a petition with your city's traffic-calming program. Most Oregon cities require a signed petition from the majority of affected residents plus a measured traffic study. On a private street or HOA road, the property owner or HOA board authorizes the install directly. See how to request a speed hump for the city-by-city process.
Get a Custom Speed Hump Quote
Cojo installs asphalt and modular speed humps across Oregon's I-5 corridor. From single-unit residential installs to multi-unit campus and HOA projects, our crews handle layout, traffic control, install, painting, and signage in one mobilization. Contact Cojo for a free site assessment and quote.