Slope on Grass Parking Lot 3

[JoeJitzu]

Hi, folks!

I'm designing a parking lot for an agri-entertainment site, specifically a farm wedding venue. Guests will be parking on grass (basically a pasture). What's the maximum slope I can have for automobile parking on grass? This venue will only have one or two weddings a week, so wear and tear should be minimal. I'd like to know the maximum slope for both unreinforced, natural grass surface, and a surface reinforced with a some type of turf paving block, like GrassCrete or some such. Service trucks (caterers, etc.) will enter via a separate gravel drive and load/unload on a flatter area, either grass reinforced with a turf paver block, or a gravel pad.

Thanks!

 

[LittleInch]

I would say 1 in 10, but what is more important is where the entrance and exit are. You don't want people setting off up the hill. That's when people spin wheels and start to skid.

This week I was at an event where they use a grass field on a decent slope. The entrance was at the bottom, you went across the hill on a stone path then up the hill at 80 degrees then every one parked facing down the hill so when you left it was easy. You really need to stone or have some sort of temporary road on the main access paths.

It'll all be ok until one day it pours down with rain. Then make sure you have a few tractors around....

Remember - More details = better answers
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[SlideRuleEra]

What's the maximum slope I can have for automobile parking on grass?
This venue will only have one or two weddings a week, so wear and tear should be minimal.

Consider acceptable grades on paved highways and bridges:
4% (1V : 25H) is good.
8% (1V : 12.5H) is pretty steep.

Agree with LittleInch, 10% (1V : 10H) is an upper limit... half that is much better.

I would not be so sure that one or two events per week will result in minimal damage to a grass surface... maybe in "dry" conditions during the growing season. Not when "wet" and/or the grass is not active.

http://www.SlideRuleEra.net

 

[cvg]

one good rain event during a wedding could render your pasture a mud pit, depends a lot on the plasticity of the soil

 

[GeoEnvGuy]

From a water erodion point of view 2% before you will see drainage channels eroding away. Unless you reinforce the entire area with grass paper.

 

[LittleInch]

Don't underestimate the low friction factor of wet grass, especially if it's just been cut. Also most people can't drive on anything other than tarmac. Guests in high heels and fancy clothes won't be best pleased at making their way through a muddy pasture.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[racookpe1978]

The caution about muddy dress shoes and open-toed slippers is worth repeating.

Gravel the entry point and the "driveway" towards the parking section.
As above, I like the idea of trying to encourage "parking downhill" when they pull out.
We ruined a grassed section beside the customer's asphalt driveway when he let construction cerws park beside the road for 5 weeks in January in upstate NY. Ground wasn't quite frozen, wasn't quite solid enough to withstand repeated tires. BUT! That was much more frequent than 1-2 or 2-3 times a week also.

Consider clearly marked parking cones or lanes with cones or posts - then shift them after each event.

 

[JoeJitzu]

Thanks, folks, for all the suggestions. I think I can keep the grade at no more than 2%. The "park facing so they pull out downhill" is a great idea, as is shifting parking and lanes after every event. Not sure how to handle the shoe problem. High heals will probably even sink into woodchip or pea gravel walks, and the owners want to install as little paving as possible. Maybe pervious concrete paths, which might count towards water quality provisions, also, which they're going to have to address.

 

[BridgeSmith]

I don't think you're going to solve the issues with high heels in your parking lot. I suggest having a drop-off point at a sidewalk on the way to the parking lot, so the ladies in high heels can get out on a smooth concrete walkway, and the guy (or a valet) can park the car out in the grass.

 

[JoeJitzu]

Thanks, HotRod10, that makes a lot of sense.