Finding the cheapest way to get to work.

The NJ Turnpike Authority raised the toll on the Garden State Parkway to $1.50.

Question: When driving to work, should I take the parkway and pay the toll, or should I take side streets in order to avoid the toll?

Assumptions: Car gets 19 MPG city and 29 MPG highway.  Gas costs $3.75/gallon.  Ignore the value of time saved, etc.

I identified three alternative routes:

1. Side streets (10.0 miles)
2. Parkway (10.9 miles)
3. Hybrid (Parkway until you get near the tolls, get off at the exit before the toll, and then get back onto the exit after the toll – 14.1 miles)

2007 Acura TL by 123 Chroma Pixels, on Flickr

Let’s examine each alternative.

Side streets

10.0 miles / 19 MPG x $3.75 = $1.97 total cost.

Parkway

10.9 miles / 29 MPG x $3.75 = $1.41 cost + $1.50 toll = $2.91 total cost

Hybrid

Assume 25 MPG.*

14.1 miles / 25 MPG x $3.75 = $2.12 total cost

Cheapest option: take the side streets.

What about driving home from work?  There is no toll.  Therefore, cheapest option to drive home would be the Parkway.

The savings per trip (Side streets versus Parkway) comes to $2.91 – 1.97 = $0.94.  Assuming I drive to work 220 times in a year, I’m saving $206.80 by taking the side streets.

* I estimated that this would be closer to the highway mileage than the city mileage because most of the route would still be highway miles.