Vertical Speed Control
ELM-VSC-06 Vertical Speed Control
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.
Are Streets Too Complicated Now?
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.
This is the key to safer streets
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.
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 (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 (ELM-NTC-46) (an alternative Local-to-Local calming treatment)