Do they allow truck parking

As long as you are nice and safe they do have RV Semi parking.. Use common sense and manners..

Regular trucks, yes. Semi trucks, no.

It has a verry nice lot and allows a lot of trucks and vehicles

Yes

Lots O Parking for ALL vehicle types!

Plenty of parking space.

The parking lot is big but if you're bringing a truck, there's a lot of space on the side. The parking slots up front are for smaller vehicles

I'm not sure but traffic is very congested in the area.

I believe so. The road into the Lehi site has a couple of tighter turns, but their lot has plenty of room to the south of the building. I don't know about the Layton site.