Have you ever noticed how hard drivers work to avoid walking? We have all seen drivers circle 
parking lots and then squeeze into a spot near the front. That spot is so tight that it requires several attempts to get backed in straight. In the meantime, less that 100 yards away is a spot that driver could have pulled into. This industry lacks a pedestrian mentality. In the real world, the pedestrian has the right of way. In a truck stop, the pedestrian is risking their life if they think that truck will stop for them.
One of the easiest ways to increase your fuel mileage is to limit your number of stops. Truckers often don't even consider walking when we can drive. I remember sitting about 9 hours into a 10 hour break in Menominee, MI. I had delivered my load the night before. From there I had to deadhead about 60 miles to Green Bay, WI. The plan was to stop on the way down to grab a cup of coffee. It wasn't a great plan. There aren't decent places to stop, but why stop at all. The idea light went off in my head. There 
was coffee available about a mile from where I was sitting. I walked to get my coffee and walked back.
That doesn't seem like that much. Little things rarely seem like that much, until you start adding them up. The old rule of thumb was that it takes a gallon of fuel to pull into a truck stop. One needs to slow down. Then you will hit at least one or two stops on the way in. After that you have to get parked. Leaving the parking lot and getting back out on the highway and up to speed reverses that process. A gallon might be a shade high in the modern truck, but it simplifies the math. Let's say that you work 250 days a year and do this every day. Fuel costs roughly $2.50 a gallon. That saves you $625 per year.
My family, might tell you that I can be a bit on the frugal side. Except for my sister, who will tell you 
that I am just plain cheap. Let's take a quick look at how much that $625 can add up to over a 30 year driving career. If you just put it into your sock drawer it will add up to $18,750. Imagine, if you put that into an annuity at 5%. That would add up to about $43,000.
Next time that you are planning a trip think about that. Walk that 2 mile round trip to get that cup of coffee. That 30 minutes of exercise could add years to your life. It is a good thing that you have that extra $43,000 in your retirement account. You are better off wearing out your shoes than burning your fuel.