Working out where water will cross a road?
Working out where water will cross a road?
(OP)
There is a mopuntain road here that winds its way down the spur of a mountain. It is a dual carriageway highway actually with a kerbed centre median
I have noticed that when it rains you find that there are some places where the stormwater will run (in a stream) from the left to the right of the road (or vise versa), obviously causing serious safety issues with cars often aquaplaning into the centre barrier. The road has SW inlets on both sides of the road depending on which way the super slopes, but they do not seem to be in the right place, hence the water crossing the road
I know that this has to do with the super-elevation and the longitudinal gradient, but have often wondered how one would go about designing for this. If you can design the path the SW will follow you can obviously put the SW inlets just upstream of where the water will cross the road.
I can only think of doing this manually by creating a contour diagram of the road surface and then obviously the water will run perpendicularly to the contours, but this seems like a bit of a novice way to do it.
Are there any texts on the subject that are available or even software that calculates this once the geometric design of the road has been done?
I have noticed that when it rains you find that there are some places where the stormwater will run (in a stream) from the left to the right of the road (or vise versa), obviously causing serious safety issues with cars often aquaplaning into the centre barrier. The road has SW inlets on both sides of the road depending on which way the super slopes, but they do not seem to be in the right place, hence the water crossing the road
I know that this has to do with the super-elevation and the longitudinal gradient, but have often wondered how one would go about designing for this. If you can design the path the SW will follow you can obviously put the SW inlets just upstream of where the water will cross the road.
I can only think of doing this manually by creating a contour diagram of the road surface and then obviously the water will run perpendicularly to the contours, but this seems like a bit of a novice way to do it.
Are there any texts on the subject that are available or even software that calculates this once the geometric design of the road has been done?





RE: Working out where water will cross a road?
Novice? - maybe - but that's the way I'd do it.
Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask
RE: Working out where water will cross a road?
RE: Working out where water will cross a road?
Otherwise manual contouring based on level information would seem to be the way to go, after the fact.
RE: Working out where water will cross a road?
RE: Working out where water will cross a road?
RE: Working out where water will cross a road?
RE: Working out where water will cross a road?
Typically a drainage guy will have the roadway designer super the road if they are designing for overtopping, at least I do. Also the crown is typically only up a couple of tenths of a foot from the edge of pavement. The crown can also act as a weir. The designer(s) just need to be logical with their designs. For instance you should never ever place a super turn-over in a sag vertical curve (I have seen this before on a freeway).
RE: Working out where water will cross a road?
I have seen this mentioned in some texts, but never seen a good explanaition of how to actually work it out
RE: Working out where water will cross a road?
On a straight stretch, it has that effect if the centerline crown in any cross section is higher than the edgre of pavement. However, this is not true at curves where the wole road is generally at a constant slope in any cross section except at the transition section where anything goes...
Just take a bunch of good elevation shots. The contours do not lie guys...
Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask