Pedestrian Clearance Calculator
Crossing length to clearance and walk timing.
What it does
Traffic signals budget seconds for feet. Pedestrian clearance divides crossing length by walking speed, then a walk interval starts the movement. Underfunded clearance strands slow walkers mid-road.
The tool above takes curb-to-curb length and design speed, then prints clearance, walk-plus-clearance total, and the pace in mph or km/h. The 7-second walk minimum and 3.5 ft/s design speed mirror standard practice.
MUTCD signal provisions with ITE timing guidance carry this same method: clearance from length over speed, walk intervals to start, countdowns to finish. Slower populations and wider arterials stretch the numbers the same formula handles.
Time what geometry demands. Refuge medians and curb extensions shorten crossings that seconds alone cannot fix; leading intervals start feet before turning cars. Feet, seconds, and concrete share the job.
How to use
- Pick imperial (ft, mph) or metric (m, km/h).
- Enter curb-to-curb crossing length.
- Enter design walking speed.
- Read clearance seconds.
- Read walk-plus-clearance total.
- Fund the total in signal timing.
Formula
- length
- Curb-to-curb crossing in ft (m metric).
- speed
- Design walking speed in ft/s (m/s metric).
Speed defaults 3.5 ft/s (about 1.07 m/s) with 2 to 8 accepted. Metric mirrors in meters with pace in km/h. The 7-second walk minimum and clearance-rate method follow signal timing practice.
Worked example
Example: 60 ft crossing
60 ft crossing at standard 3.5 ft/s walking speed.
- Crossing is 60 ft at 3.5 ft/s.
- Clearance: 60 / 3.5 = 17.1 s.
- Walk interval adds 7 s minimum.
- Total: 17.1 + 7 = 24.1 s.
- Pace equals 2.4 mph.
Reference table
| Width | Clearance | With walk |
|---|---|---|
| 20 ft | 5.7 s | 12.7 s |
| 40 ft | 11.4 s | 18.4 s |
| 60 ft | 17.1 s | 24.1 s |
| 80 ft | 22.9 s | 29.9 s |
| 100 ft | 28.6 s | 35.6 s |
Limits
- Standard practice math, not a stamped timing plan.
- Assumes steady walking; wheelchairs vary.
- Grade, medians, and platoons complicate.
- Local standards may slow the design speed.
Common mistakes
- Timing for average instead of slow walkers.
- Skipping the 7 s walk interval.
- Measuring lanes instead of curb to curb.
- Ignoring medians as refuges.
- Starting pedestrians on clearance.
Try it yourself
Quick checks. Answers sit tucked under each question.
Clearance for a 40 ft crossing?
Clearance is 40 / 3.5 = 11.4 s. Total with walk is 18.4 s at 2.4 mph.
Clearance for a 12 m crossing at 1.07 m/s?
Clearance is 12 / 1.07 = 11.2 s. Total with walk is 18.2 s at 3.9 km/h.
Questions
How is crossing time figured?
Crossing length divided by walking speed, standard 3.5 ft/s. A 7-second walk interval starts the crossing; clearance finishes it. Total signal time is both together.
What walking speed applies?
3.5 ft/s for general design, slower where older pedestrians dominate. Faster walkers finish early; signals serve the slowest starters, not the average.
How long is the walk interval?
At least 7 seconds of walk indication before clearance starts, per signal standards. Short blocks and wide arterials both honor it.
Do countdown signals matter?
Yes: countdowns show clearance remaining so walkers judge finishing versus starting. Nobody should start on clearance; everyone inside should finish on it.
What changes on wide arterials?
Longer clearance with the same walk: 100 ft needs 28.6 s of clearance alone. Wide roads trade green time for feet, which retiming must fund.
What helps slow walkers most?
Slower speeds, medians as refuges, curb extensions that shorten the crossing, and leading intervals that start walkers first. Time plus geometry beats paint alone.