---
title: "Vertical Speed Control"
url: "https://commonwaysystem.org/patterns/elements/vertical-speed-control/"
id: "ELM-VSC-06"
description: "A raised roadway feature (speed hump, speed table, or speed cushion) that slows vehicles through vertical deflection, forcing a driver to reduce speed to avoid an uncomfortable jolt."
updated: "2026-09-26"
---

# Vertical Speed Control

`ELM-VSC-06`

Recommended Element

Vertical Speed Control

A raised roadway feature (speed hump, speed table, or speed cushion) that slows vehicles through vertical deflection, forcing a driver to reduce speed to avoid an uncomfortable jolt.

## Related Media

The items below come from outside the Commonway System, external videos, podcasts, and articles related to this page's topic, not part of the guidebook itself.

Aligned

### [Are Streets Too Complicated Now?](https://www.youtube.com/watch?v=u1Xs5EA5_uU)

City Beautiful

Asks whether today's proliferation of lines, signals, and lane types on streets is overcomplication or a needed response to modern demands, a question that runs directly through CS's Element-scale catalog and the density-tiered Corridor retrofit paths this video is tagged to.

Aligned

### [This is the key to safer streets](https://www.youtube.com/watch?v=xsSp8gxzfjo)

Streetcraft

A full traffic-calming toolkit walkthrough, plastic mini-roundabouts, curb extensions, chicanes, the speed bump/hump/cushion/table family, and a Cincinnati road-diet case study with dramatic before/after crash data.

Aligned

### [Three ways to FIX a STOP LIGHT (so drivers ACTUALLY STOP!)](https://www.youtube.com/watch?v=uYnEdbRLmJM)

Road Guy Rob

The video covers practical signal-design fixes that cut red-light running, from better visibility to slower approaches and fewer stops. It is applied evidence for the Commonway System's signal intersection pattern.

Aligned

### [A Flaw In Street Design May Be Costing Lives - Cheddar Explains](https://www.youtube.com/watch?v=yyWYvovLvMQ)

Cheddar

The video explains "forgiving design," the wide clear zones built for driver error, and draws the roads-versus-streets distinction. It covers the design-speed thinking at the heart of the Commonway System's street types and design speed guides.

Aligned

### [20mph speed limits do save lives, and most road users respond to them well, study suggests](https://www.sciencefocus.com/comment/20mph-speed-limits-save-lives)

BBC Science Focus

The article reports on a study of Edinburgh and Belfast showing citywide 20 mph limits cut road deaths by nearly a quarter and serious injuries by a third. It backs the Commonway System's signature 20 mph maximum on local streets.

## Why this pattern exists

Signage and paint alone rarely change driver speed on their own; a physical vertical deflection imposes a real cost on speeding that self-enforces without requiring active enforcement presence. This pattern exists to document the distinct forms this treatment takes and where each is appropriate, since a hump, table, and cushion serve different vehicle types and roadway contexts differently.[1]

## Key considerations

-   Form should match context: cushions allow emergency vehicles and buses to straddle them with less impact than a full-width hump or table
-   Placement and spacing should be based on desired speed and roadway geometry, not applied as a one-size-fits-all interval
-   Drainage and snowplow operations need consideration in colder climates, since a raised feature can interfere with both

## Related patterns

[Rumble Strip](https://commonwaysystem.org/patterns/elements/rumble-strip.md) (ELM-RMS-07) (a related but distinct calming treatment using texture rather than vertical deflection); relevant Local and Collector Segment patterns where speed control applies; [Neighborhood Traffic Circle / Mini-Roundabout](https://commonwaysystem.org/patterns/elements/neighborhood-traffic-circle-mini-roundabout.md) (ELM-NTC-46) (an alternative Local-to-Local calming treatment)

## References

1.  Precedent-based [Institute of Transportation Engineers, _Guidelines for the Design and Application of Speed Humps_ (updated edition).](https://ecommerce.ite.org/iCommerce/iCommerce/Orders/Item_Detail.aspx?iProductCode=RP-038A)