Any transportation gurus here? Driveway Aprons purpose. 1

[Bhotar3]

I serve on local govt in my county. We have an industrial facility that has large gravel drives accessing a main road. They're requesting a variance for the required concrete aprons at the access point. Their argument is because they have heavy haul equipment and in their experience the aprons get damaged over time (I'm calling BS. Just design them better)

I'm no transportation Engineer, and I've done limited research. What's the purpose of the concrete apron, and what are the risks if they do not have them apart for gravel in the roadway?

I appreciate the help.

 

[3DDave]

I expect there can be a depression in that gravel allowing heavy vehicles to slam into the side of the public road, damaging the public road. They may want that damage to be not their problem. If it is chewing the side of a private road then it may make no difference. If they are concerned about the apron getting damaged it just means they don't want to pay for repair regardless of the installation price.

Consider that roads aren't meant to have a single point where multiple tires slam into a small area. The apron is the defense against that.

 

[JLNJ]

In addition to the above, concrete resists the scrub from turning truck tires and drains better when it rains.

 

[lexpatrie]

It drains better but more so it doesn't spontaneously erode over time to remotely the same rate. Impact loads from the axles on the legit road, etc. Petty hostile design for the truck drivers, too, what with a dodgy gravel turnaround to get to the loading dock, but whatever.

 

[dold]

Yeah pretty much what 3DDave said. "we don't want to build the approach because our trucks beat the crap out of the concrete, so we'd rather beat the crap out of a county road so the county pays to repair it."

The whole point of the concrete approach is to protect the edge of the roadway. Otherwise it gets rutted out, fills up with water, water gets under the roadway, roadway subbase fails, roadway fails.

VARIANCE DENIED!!!

 

[Bhotar3]

For fun, here's Google street view of the subject entrances.

Apparently, these have existed this way for a number of years, and for some reason this is a new issue. I think the original site plan had them including the Aprons, and they never did.

But you can clearly see the potholing adjacent to the curbs, and some of the curbs are cracked up in some spots.

 

[CarlB]

An apron also reduces amount of gravel that gets carried onto the road, which can be a safety hazard and projectile for windshield damage.

 

[gte447f]

Their argument for why they need a variance (that the aprons get damaged over time) is actually justification for why the aprons are required in the first place. It's because the without the aprons, that damage might occur to the roadway instead. The aprons are a protective measure for the roadway. You could grant them the variance if they agree to pay for all future maintenance and replacement costs for the roadway within the limits of the project area (just kidding sort of).

 

[Bhotar3]

You nailed my feelings exactly. I appreciate everyone's feedback. I will post later this evening following the results of the variance vote!

 

[3DDave]

Kick in that if/when the roadway needs to be replaced, it will affect local traffic and may decrease the safe use of the remaining road while the repair is being made. This will also limit access to their facility during the repair.

Good luck.

 

[Bhotar3]

Update:

Variance denied unanimously

 

[dold]

Variance denied unanimously

That is very satisfying to me.

 

[LittleInch]

Good work.

Just don't double post next time....

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