Do you charge a fee to travel?

We have been invited to be the sole vendor at a 2 day event in our town. The event is only 4 miles down the road from our usual semi permanent location but with fried foods we will have to drain down the fryolators to travel back and forth. The event will only have about 100-150 people (prety much captive audience) and we have to use generator power vs our usual line power. All profits from sales are ours to keep. Should I charge the event a fee to be there? If so what would you charge.
 
We will be there 8am-3:pm then back to our usual location until 9:pm because we have our best ice cream sales late in the day on the weekends and would hate to p.o. our usual customers by not being there. We have a 20' trailer so it is quite heavy to tow.

I would not even bother with 100 people... Thank them and move on. Let them know that amount of people is not worth the work it takes to move your trailer.
On the fee...no, you are a mobile vendor showing up to vend, it's what you do.
Don't get known in a small town for wanting to charge people to move your mobile kitchen. You will never get any side work.
 
If you were a caterer, charging by the head and you had a long distance to go, you might be able to add something in there.
Draining the fryer is not a big deal. Drain in to a stock pot, down to the burners and let it ride in the sink.
I do it all the time, only takes a minute.
I also have a 20' trailer, last time I weighed it, was close to 14,000lbs....not a problem to move around if you have the right tow vehicle. Mine will go down the hwy at 70 mph no problem.

Why not switch your menu up to something that can be managed under a pop up tent for the event?

Why not switch your menu up to something that can be managed under a pop up tent for the event?

Why not switch your menu up to something that can be managed under a pop up tent for the event?

We will change the menu a bit but our main draw is our corn dogs and our ice cream. Neither of which we can do without the fryolator and the dipping cabinets coolers.
 
The charge for being there is to cover the low attendance more than anything to make it worth me moving the trailer.
 

Usually don't start to think of charging for under 50 miles. I'm a little different only doing things on site with permanent location.

sORRY FOR STUTTERING 

Me being a newbie I would take the business...any business I could get to get the exposure...4 miles doesnt seem that far to me at all and it is in your town so why not do it

An update on this post:
 
We did not charge the promoters to be at the event. It was a dog show and because we sell a variety of foods we were the only ones selling food there. There were only about 75 people there each day for 2 days but we actually did well as far as sales and profits goes. We did rise our prices slightly to compensate for the hassle of moving the trailer. All in all we will probably only do special events like this and fairs next year. It is much better to sell to a captive audience than be sitting on the side of the road and pay help to sit around all day and deal with the water issues on a daily basis.
 
We are doing a fair this weekend. Last night it was cold and rainy so noone was there. The fair even closed an hour early. The rest of the weekend should be really nice weather so hopefully we will see some big crowds.