What is the distance between Trenton MI and Farmington MI?

It is 33.5 miles according to google Maps taking this route:

1. Go over to I-75, and follow signs to I-75 NORTH.
2. Take I-75 NORTH to M-39 SOUTHFIELD RD at EXIT 41; turn left off the exit ramp onto M-39 NORTH.
3. Take M-39 NORTH, on Southfield Rd, and on the Southfield FREEWAY, to I-96 WEST to LANSING at EXIT 11.
4. Take I-96 WEST to FARMINGTON RD at EXIT 174; turn right off the exit ramp onto Farmington Rd going NORTH.
5. Go up Farmington Rd to FARMINGTON.