Ramp slopes 1

[pqh]

I am looking for general guidelines for maximum slopes on vehicular ramps. I found a city standard that said 20% (not the city or state I live or work in). That seemed a little high to me. I have 3'3" I have to come down from(possibly more depending on the slope of the terrain where the ramp will meet existing grade). I am limited in the horizontal distance I can travel though. Any help would be appreciated.

 

[cvg]

driveways are usually limited to about 12%

slope is limited by the vehicle size and type, length of ramp and the breakover angle at top and bottom of the ramp which causes high centering and bottoming out

ADA also has significantly more limitations on the slope

 

[WL123]

You might want to take a look in "Architectural Graphics Standards," I don't have a copy, but I know the have some ramps in it. Mainly for parking garages, I think it might go up to 16% with approach mini ramps at less of a slope to prevent bottoming out as CVG said. We had used it as a guide for doing an outside ramp down into a garage for multiple cars and it worked fine after construction. I've been out of work, so I don't have access to the book.

 

[MiketheEngineer]

ADA is 12:1 plus a lot of other requirements

 

[HockeyPuck]

Usually, an 8% maximum rollover break on cross-section slope needs to be maintained(say 6% down left and 2% down right) to keep the vehicle from bottoming-out on a crown. The same would apply for a driveway connection: Too steep of a driveway connection and you'll have front/rear bumpers hitting the leading edge. I think the 16% that WL123 suggests is too large.