Bus trap

A bus trap in Denmark

A bus trap in northern Aarhus, Denmark

A bus trap is a metal grate placed over a ditch or pit in the road with tines (sides) spaced far enough apart that small-diameter-wheeled (narrower axle) vehicles fall in between the tines but close enough that larger-diameter-wheeled vehicles, such as buses, may pass. Cycles may cross broader sided examples.

Different versions exist for restricting access. The tines cross the path of the road, not parallel with the road direction. Small-wheeled vehicles bottom out in between the tines, preventing the vehicle from continuing over the obstacle.

Deprecation and preferred alternatives

Many domestic vehicles exist in the 21st century wide enough to navigate bus traps effectively; wide-axle SUVs and 4x4s. Police cars and in some cases motorbikes are hindered by bus traps. Most cities favour other means of keeping cars out of bus-only areas, such as:

• fines backed up with camera enforcement
• a controlled barrier — may use radio-frequency identification
• a rising clearly marked bollard kept in a default risen state (Rfid) — may use radio-frequency identification

See also

• Sump buster
• Cattle grid