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.
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. -
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.