Speed humps

[BZG]

Is there a specific technical reason of putting humps (road speed humps) on bridges approaches? I was driving on one trunk road which have a speed limit of 80km/hr and encounter speed humps on bridge approach roads whenever there is a long span bridge.

 

[Debaser]

I would have thought 80kph (50mph) is very high to allow speed humps or any vertical traffic calming, usually the upper limit is 30mph (48/50kph).

 

[ACtrafficengr]

Are you sure it was a speed hump, or was it simply settlement of the fill behind the abutment? The latter is a common problem. The former is a practice I've never heard of.

Maybe the tyranny of Murphy is the penalty for hubris. -

http://xkcd.com/319/

 

[BZG]

Sorry, the posted speed limit near the approaches is 50km/hr, I was just wondering if it is necessary to calm traffic passing on a bridge which is wide enough for vehicles to pass at 80km/hr. I noticed that the humps are provided when the bridge exceeds 50m span.

 

[Debaser]

Do you have a GoogleEarth link/location for this bridge?

I've never otherwise seen calming actually on a bridge deck.

 

[Drumchaser]

Could be incorrect grade/profile on the armor joint(s)

 

[TomDOT]

Humps are generally a pretty terrible solution.