I recently went from a commute that was 95% highway to another commute that is also 95% highway. However, the first commute was a congested route that I had to endure and the second route is almost always smooth traveling at highway speeds (toll highway).

I’m a guy that’s obsessed with numbers and I’m cheap, so I’m trying to calculate where I stand after moving from the congested route (that is free) to the smooth route (that is toll).

I can venture to say that my MPG on the smooth route, depending on how heavy my foot is, will be close to the EPA highway MPG so that is the assumption I’m making for the toll road.

I can’t seem to find any agreed-upon hit to your MPG or equation to calculate your MPG for congested highway traffic. We’re talking average speeds of 30-35mph on the highway, with random stops and goes, level of congestion.

Has anyone done the math? Is congested highway MPG closer to the EPA city rating, EPA highway rating? The middle?