Recently I noticed a concrete speed bumper created near my parking. On enquiring the purpose, the committee who took the decision told me that the purpose of the bumper is to safeguard an existing pipeline below the bumper from heavy vehicles. Some significant points:

  1. Existing road in the complex is made up of concrete and is plain. The road has not suffered any damage from any heavy vehicle in past.
  2. The pipe is made up of polypropylene or some similar material. The diameter of pipe is about 6 inch. It is there to direct the water collected from roofs to rainwater harvesting reservoir.
  3. Speed bumper is solid and made up of concrete.
  4. Heavy vehicle here is a water tanker truck with capacity in multiples of kilolitres (Usually 5KL) filled to the top with water.

Is it necessary to raise such a speed bump to prevent any harm to pipeline below concrete plain road? Is it helpful, has no effect or worse in avoiding impact on the pipeline below?

  • $\begingroup$ How far below the road surface is the pipe buried? $\endgroup$
    – Solar Mike
    Sep 11, 2019 at 7:19
  • $\begingroup$ I am not sure. I believe about 5 to 8 inch. $\endgroup$
    – Mohit Jain
    Sep 11, 2019 at 8:51
  • 1
    $\begingroup$ If it's a short speedbump directly over the pipe, it makes it worse. If it is more tabling than speedbump, it can help bridge the pipe. It would need to be pretty wide - like ten feet wide. If you need to run a pipe under an asphalt road, just put a speed bump there six months before you need to run the pipe, and you will be able to shovel out the ruined pavement when you want to run the pipe. Nice clean edges too ;) $\endgroup$
    – Phil Sweet
    Sep 11, 2019 at 10:02
  • $\begingroup$ @Phil The speed bump is about 2-2.5 feet wide. Can you please write an answer? $\endgroup$
    – Mohit Jain
    Sep 11, 2019 at 10:07
  • $\begingroup$ Can you confirm if the speed bump is directly over the top of the pipe? A bump a short distance away may serve to reduce average traffic speed without transferring 'impact forces' directly to the pipe $\endgroup$ Sep 16, 2019 at 17:52

2 Answers 2


A speed bump not only does not help to protect a submerged pipe, but it may also even damage it more because of the impact of heavy truck axle hitting and falling down from the bump after it just has crossed it.

An axel impact on hitting a flat landing area after dropping the face of a speed bump can be several times the weight of the axel. While an axel just passing on, will push the road just barely more than its weight depending on its speed and tire air pressure and some other small factors. We all experience the discomforting jerk on the suspension when we dismount a bump. Some people as a reflex brake partially after the tire rolls down the bump which makes things worse because of the car balking.

The only way that something looking like a speed bump can help is when it spans the pipe, not installed before it and has been actually engineered to work as a bridge such as a bilaterally tapered concrete slab designed with foundations saddling the pipe and adequate rebars.


If the pipe is buried sufficiently deep (more than 18" for example) then no speed bump will be needed. Otherwise all the roads would be continuous speed bumps in many countries...

If the pipe has to be close to the surface due to the fall it needs then yes a speed bump or hump may well be necessary to get the traffic over it without damage.

  • $\begingroup$ Is this answer valid for the short speedbump, just above the pipeline and laid after the pipeline? Or we need to construct the bridging bump carefully about 6 months before laying the pipeline as mentioned in other answer and comments? $\endgroup$
    – Mohit Jain
    Sep 18, 2019 at 6:36
  • $\begingroup$ You need to evaluate the answers to your situation. I gave you mine... $\endgroup$
    – Solar Mike
    Sep 18, 2019 at 6:53
  • $\begingroup$ Thank you for writing it and sorry for bothering you. I just want to know whether this bump or hump can be created later also or it must be planned in advance to provide a nice bridge? $\endgroup$
    – Mohit Jain
    Sep 18, 2019 at 7:01
  • $\begingroup$ According to your question it already exists... $\endgroup$
    – Solar Mike
    Sep 18, 2019 at 7:34
  • $\begingroup$ I was a little unclear on that part. It was laid about 2-3 weeks after installing the pipeline. Edited the question to remove the ambiguity. $\endgroup$
    – Mohit Jain
    Sep 18, 2019 at 8:34

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.