Doing the standard click on the map business, you get three different options on this page, (sorry for using evil demon Google),,,
East Brunswick, NJ to Summit, NJ - Google Maps
Now if you select various other options, such as "Show Options" avoid highways or avoid tolls, or both, you will get back roads, etc.
I always like to have at least one other option, usually a few more.
The 3rd choice above has you hopping off the G around Clark, going thru Westfield, etc.
Avoid highways gets you in like this:, mostly backroads in sort of a straightest line routing.
East Brunswick, NJ to Summit, NJ - Google Maps
Also you can mouse around and change the route and try other map sites.