A speed cushion installation is a 7-step procedure that runs from layout and traffic control through anchor placement, cushion seating, and final pavement marking. The Federal Highway Administration's Traffic Calming ePrimer Module 3.4 and the Institute of Transportation Engineers (ITE) Traffic Calming Manual, Chapter 3, define the geometry; local fire-marshal sign-off defines the wheel-track gap. The procedure below covers a modular rubber cushion install, the most common configuration in Oregon.
Tools and Materials
- Chalk line and 100-foot tape measure
- Hammer drill with 5/8-inch concrete bit (or asphalt anchor spike for asphalt pavement)
- Torque wrench rated to 50 to 100 ft-lb
- Anchor hardware per manufacturer specification (concrete anchors or asphalt spikes plus epoxy)
- Modular rubber cushion sections (typically 3 sections per cushion)
- Pavement marking paint or pre-formed thermoplastic
- Advance warning signs per MUTCD W17-1a
- Traffic-control hardware (cones, flagger paddles, advance warning signs)
Time and Crew
- Crew: 3 installers plus 2 flaggers
- Time on site: 3 to 5 hours per single cushion, 1 working day for a set of 3
- Cure time: none (rubber cushions are anchored, not poured)
Step 1: Verify Layout and Wheel-Track Gap
Confirm the cushion location with the engineering drawing or city traffic-calming application. The cushion centerline must be perpendicular to traffic flow, and the wheel-track gaps must be sized to the local fire department's apparatus axle width (commonly 1.85 meters / 72 to 73 inches outside-to-outside). Mark the cushion footprint on the pavement with chalk lines, including the gaps. Per NFPA 1141 chapter 5, the wheel-track gap is the dimension that preserves fire-apparatus access; do not shortcut its placement.
Step 2: Set Up Traffic Control
Position advance warning signs (MUTCD W17-1a "BUMP") at 100 to 200 feet upstream of the work zone in each direction. Place cones to define the work zone. Station flaggers at each end. The work zone for a single cushion is typically 30 to 40 feet long; for a set of three cushions on the same corridor, the work zone may extend 200 to 400 feet. Per MUTCD Part 6 work-zone standards, advance warning sign spacing scales with posted speed.
Step 3: Inspect and Prepare the Pavement
Visually inspect the pavement under the cushion footprint for cracking, oxidation, and rutting. Modular rubber cushions need a flat, intact surface for anchor torque to hold. If pavement under the footprint is damaged, spot-repair before placing the cushion. The Asphalt Institute's MS-16 maintenance manual guidance on crack-seal and surface treatment applies. Clean the footprint with a power broom; loose aggregate prevents the cushion from seating flat.
Step 4: Position the Cushion Sections
Lay out the rubber cushion sections in their final positions per the chalk-line layout, including the wheel-track gaps. Do not anchor yet. Verify that the gaps measure exactly to the spec from Step 1. Verify that the cushion centerline is perpendicular to traffic flow. Verify that any drainage is preserved (cushions on a crowned street need to allow water to flow across, not pool against, the cushion edge).
Step 5: Drill Anchor Holes and Set Anchors
With the cushion sections positioned, mark anchor hole locations through the cushion's pre-drilled holes onto the pavement. Lift the section, drill anchor holes with the hammer drill, vacuum out debris, and set the anchors. For concrete pavement use mechanical concrete anchors (typically 3/8-inch by 4-inch) with manufacturer-specified embedment depth. For asphalt pavement use asphalt anchor spikes with two-part epoxy. Per the Asphalt Pavement Alliance anchor placement guidance, anchor pull-out strength is the limiting factor in asphalt; epoxy-set spikes outperform mechanical anchors.
Step 6: Re-Position, Anchor, and Torque
Place each cushion section back over its anchor pattern and tighten the anchor bolts. Torque each bolt to the cushion manufacturer's specification (typically 30 to 60 ft-lb depending on bolt size). Verify final torque after all anchors are set. Cushion sections should sit flush against the pavement with no rocking; any rocking indicates inadequate pavement preparation in Step 3.
Step 7: Install Pavement Marking and Signage
Paint or apply chevron markings on the cushion top per MUTCD Section 3B.26 hump and bump marking standards. Yellow chevron stripes 6 inches wide, alternating with the cushion's existing reflective tape, are the typical configuration. Install permanent advance warning signs (MUTCD W17-1a) at 100 to 200 feet upstream in each direction, replacing the temporary work-zone signage. Verify all reflective tape and signage is intact before tearing down traffic control.
Verification Checklist Before Demobilizing
- [ ] Wheel-track gaps measured and within specification
- [ ] Cushion centerline perpendicular to traffic flow
- [ ] All anchors torqued to manufacturer specification
- [ ] No rocking when stepping on each cushion section
- [ ] Drainage flow path preserved
- [ ] Pavement marking applied per MUTCD
- [ ] Advance warning signs installed at correct upstream distance
- [ ] Reflective tape intact and aligned
How Is This Different from a Speed Hump or Speed Bump Install?
A speed cushion install differs from a speed hump or speed bump install in three procedural ways:
- Wheel-track gap measurement is the critical dimension; humps and bumps span the full lane and have no equivalent gap to verify
- Cushion sections are pre-fabricated and anchored, not poured; the installer is not running asphalt paving equipment
- Fire-marshal sign-off on wheel-track gap is typically required before traffic control demobilizes
Speed hump and speed bump installs are documented in their own how-to articles. For the cushion-specific dimensions used in Step 1 see speed cushion dimensions, and for fire-marshal coordination context see speed cushion fire truck access.
From Our Crew
In late 2024 Cojo installed a set of three modular rubber speed cushions on a Tigard fire-access greenway. Tualatin Valley Fire & Rescue specified the wheel-track gap at 1.85 meters based on their tower-truck axle measurement, and the engineering review attached a layout drawing keyed to that dimension. Our crew laid out the chalk lines first, then walked the layout with the city traffic engineer before drilling anchor holes. Anchor bolts were torqued to 45 ft-lb per the manufacturer specification, and we re-checked torque at the 12-month mark, which is standard practice in the Willamette Valley freeze-thaw zone.
Safety Warnings
- Never install a speed cushion without an approved traffic-control plan; flagger placement and advance warning signage are required even for short work zones
- Verify the wheel-track gap with the local fire marshal before committing to anchor pattern; a wrong gap is not field-correctable without removing the cushion and re-drilling pavement
- Do not install a rubber cushion over a damaged pavement section; anchor pull-out is significantly higher and the cushion will rock under load
- Always verify current MUTCD and local jurisdiction requirements before specifying signage; standards change
Or Hire Cojo's Installation Crew
Cojo installs modular rubber, asphalt, and concrete speed cushions across the Oregon I-5 corridor. We coordinate the city traffic-calming application packet, field survey, traffic control, anchor placement, and pavement marking in one scope. For the labor breakdown see speed cushion installation cost, or pair the install with our asphalt maintenance services. For Portland-area installs see Speed Cushion Installation Portland. Get a custom quote.