Driving across a board

I apologize ahead of time if this question has been asked or sounds stupid.

A buddy and I are planning on heading out to the Salton Sea this weekend. Last weekend we were there we ran across a ditch that was a few feet deep and probably 3-4 feet wide. We're planning on heading out there this weekend again but we plan to cross this ditch we are looking for recommendations on lumber size that would be safe to drive across.

The ditch is too deep for him to drive down into without hitting the bumpers and he has a 97 Tacoma 4x4.

This will just be a temporary bridge that we can throw down and put back in the bed when were done using it

 

Staging plank would probably do ya. Well a few...

 

Personally I would go with at least 2x12's (2 nailed together) with 2 4x4's supporting the center (spaced evenly) for each side of the vehicle.

 

Thanks guys I tried to look all over the internet and couldn't find anything, only info I found was info about building wooden garages that have to support the weight of a vehicle resting