That limit is completely reasonable on the NJ turnpike especially considering that the cultural norm is to go 5-10 mph over. American speed limits are determined with the expectation of drivers going over. In other countries the limit is more literal.

No cop is going to ticket you for going 70-75 on the turnpike.

In my town you don't get a ticket unless you are going 10mph over, and this is on surface streets. They might be stricter in the 20mph school zones though.