Asphalt speed humps win on lifecycle cost (15 to 25 year lifespan) and integration with surrounding pavement (mills and re-screeds during normal pavement-management cycles). The choice within asphalt comes down to cross-section profile. Five profiles dominate U.S. residential traffic-calming work in 2026, each with a specific operational fit. Our crew defaults to the Watts profile for typical Oregon residential streets and pivots when conditions warrant.
Selection criteria
Cross-section profile selection depends on:
- Target speed. 15 mph profiles are more aggressive; 20 mph profiles are gentler.
- Cyclist traffic. Sinusoidal beats parabolic on bike comfort.
- Bus or fire-access. Flat-top profiles let long-wheelbase vehicles ride flat.
- Pavement-management horizon. Asphalt profiles can be milled and re-screeded as part of overlay cycles.
- Climate. All asphalt profiles need the right binder grade for local freeze-thaw conditions.
1. Watts profile, 12 ft (default residential)
The Watts profile is a parabolic cross-section developed at the UK Transport Research Laboratory and adopted as the U.S. residential default. Length: 12 feet. Height: 3 to 3.5 inches. Target speed: 15 to 20 mph.
The profile's smoothness gives consistent slowing across a wide speed range, with fewer driver complaints than steeper alternatives. ITE Traffic Calming Manual Chapter 3 references the Watts profile as "the most widely deployed residential speed hump" in U.S. practice.
Best for: Standard residential collectors, local streets, HOA neighborhoods.
2. Seminole profile, 14 ft (gentler)
The Seminole profile (developed by Seminole County, Florida) extends the Watts geometry to 14 feet, reducing the slope at the leading and trailing edges. Slowing performance is roughly equivalent to Watts at 15 to 18 mph, with reduced suspension articulation for cars.
Best for: Streets with high volumes of older drivers, accessibility-priority neighborhoods, and any site where reducing driver complaints matters more than the last 1 to 2 mph of slowing.
3. Sinusoidal profile, 14 ft (cyclist-friendly)
A pure sine-curve cross-section across 14 feet. The Federal Highway Administration's Traffic Calming ePrimer documents better cyclist comfort with sinusoidal humps on streets that double as designated bike routes (FHWA ePrimer). Slowing performance for cars is similar to parabolic profiles.
Best for: Streets that are part of a designated cycling network, including Portland's bike-greenway system and Eugene's neighborhood greenways.
4. Flat-top profile, 22 ft (transit-compatible)
Technically a speed table, but commonly grouped with humps when the residential application calls for transit or fire-truck compatibility. The 22-foot flat top lets buses ride at 20 mph and fire trucks at 22 to 25 mph.
Best for: Residential collectors that carry buses (TriMet, Lane Transit, Salem-Keizer Transit) or that the local fire bureau identifies as primary apparatus access.
5. Hybrid asymmetric profile, 12 ft (one-way streets)
An asymmetric parabolic profile with a steeper trailing edge. Designed for one-way streets where drivers approach in a known direction; the steeper trailing edge discourages re-acceleration. Slowing performance is about 2 mph better than symmetric profiles in field tests.
Best for: One-way residential streets, dead-end approaches, school drop-off lanes with directional traffic.
How to pick between them
Three questions in order:
- Does the street carry buses or priority fire traffic? If yes, profile 4 (flat-top). If no, continue.
- Is the street part of a cycling network? If yes, profile 3 (sinusoidal). If no, continue.
- Is driver complaint risk a stated concern? If yes, profile 2 (Seminole). If no, profile 1 (Watts) is the default.
Profile 5 (hybrid asymmetric) is a niche pick for known one-way streets and rarely shows up in standard residential work.
In a 2025 install for the City of Eugene, our crew used profile 3 (sinusoidal) on a neighborhood greenway because the street is a designated cycling corridor and the city's traffic-calming program preferred the cyclist-friendly profile. For a typical Lake Oswego residential install in March 2026, the same crew used profile 1 (Watts) because no transit, fire, or cycling priority existed on that street.
What it costs
Industry Baseline Range
| Profile | Length | Installed Cost |
|---|---|---|
| Watts profile | 12 ft | $1,500 to $4,500 |
| Seminole profile | 14 ft | $1,800 to $5,000 |
| Sinusoidal profile | 14 ft | $1,800 to $5,500 |
| Flat-top (speed table) | 22 ft | $5,000 to $15,000 |
| Hybrid asymmetric | 12 ft | $1,800 to $5,000 |
Current market reality
Asphalt-hump pricing in 2026 reflects roughly 18% hot-mix cost increases over 2024 baselines plus tight traffic-control labor in Oregon's I-5 corridor. Multi-unit projects (3+ humps on the same street) typically save 15 to 25% on per-unit pricing because mobilization, traffic control, and pavement marking efficiencies compound across units.
What about pavement marking?
Every asphalt hump receives yellow chevron pavement marking on the leading face plus a W17-1 advance warning sign 100 to 200 feet upstream per the Manual on Uniform Traffic Control Devices (MUTCD). Some jurisdictions require additional reflective markers embedded in the hump surface; check the local traffic-calming program spec.
For full painting and marking detail, see the speed hump painting guide.
Frequently asked questions
What is the most common asphalt speed hump profile in the U.S.? The Watts profile (12 ft parabolic) is the most widely deployed. ITE's Traffic Calming Manual Chapter 3 references it as the U.S. residential default.
How long does an asphalt speed hump last? 15 to 25 years with normal traffic. The asphalt itself can be milled and re-screeded as part of routine pavement-management cycles, so the device remains in place across multiple resurfacing cycles.
Can the asphalt speed hump profile be changed after install? Yes, by milling and re-screeding. A Watts profile can be milled flat and re-screeded as a Seminole or sinusoidal profile in a 1-day operation. Cost is roughly half of a fresh install.
Is the sinusoidal profile worth the upcharge? On dedicated bike-route streets, yes. On general residential streets without designated cycling traffic, the parabolic profile (Watts or Seminole) delivers equivalent slowing at lower cost.
Do all asphalt humps need a chevron paint pattern? Yes, per MUTCD. The W17-1 advance warning sign and yellow chevron pavement marking are standard practice and required by most Oregon city traffic-calming programs.
Specify the Right Profile
Cojo installs all five profiles across Oregon. We coordinate with city traffic engineers to pick the profile that matches the street's traffic, cycling, and transit conditions. Contact Cojo for a quote, or see how to install speed humps for the full procedure.