What is the difference between a speed bump and a speed hump?

A bump is short and abrupt — a few inches over a foot or two — and forces a near-crawl, which suits parking lots. A hump spans ten to fourteen feet and slows traffic to a moderate speed. Most communities asking for bumps actually want humps.

Do speed humps affect emergency vehicles?

Yes, they slow fire and EMS response, which is why it is worth talking to your local department before installing. Speed tables — flat-topped and long enough for a whole vehicle — are gentler on emergency vehicles while still calming general traffic.

Speed Bumps, Humps and Tables: What Actually Works on Community Roads

Traffic calming is one of the most common requests we get from HOA boards and property managers, and the terminology gets used loosely in a way that leads to the wrong device being installed.

The three devices

Speed bump

Short and abrupt, a few inches high over a foot or two of length. Forces vehicles to a crawl. Appropriate in parking lots and private drives where speeds should be very low. Genuinely unpleasant at anything above walking pace, which is the point — and also why it is wrong on a through road.

Speed hump

Longer and gentler, typically spanning ten to fourteen feet. Slows traffic to a moderate speed rather than a crawl and is far more appropriate on residential streets. This is usually what a board actually wants when it asks for speed bumps.

Speed table

A hump with a flat top, long enough for a whole vehicle. Slows traffic while being kinder to emergency vehicles, and it can double as a raised crosswalk. The most expensive of the three and often the best on a road with genuine pedestrian traffic.

Ask for a bump and get a bump, and residents will complain about the bump. Most communities want a hump.

What to consider before installing anything

Emergency access. Fire and EMS response is slowed by aggressive calming. Talk to your local department before installing.
Drainage. A device across the road is a dam. Placement has to account for where the water goes.
Signage and markings. An unmarked device is a liability. It needs visible markings and advance warning.
Placement. Not on a curve, not on a steep grade, and not where a driver cannot see it in time.
Alternatives. Narrowing, chicanes, better signage and enforcement sometimes achieve the objective without a physical device.

Maintenance

Calming devices take concentrated impact and need their markings refreshed more often than the surrounding road. Faded markings on a speed hump are both less effective and more of a liability than no hump at all.