Well, the off the shelf evil racist censor of free speech and opinion Google Maps quotes it as about 29.8 miles in 38 minutes or 26.6 miles 43 minutes, the second way getting off the 2 by 4 (NJ24) and taking the shorter back roads. Keep in mind these are during non rush hour times.
Are you looking to buy in Randolph or find something in Cranford?
All in all it is a fairly average commute for NJ, shorter than many.
Here's one:
https://maps.google.com/maps?saddr=R...ra=ls&t=m&z=11
And the shorter short cut:
https://maps.google.com/maps?saddr=R...t=m&z=11&via=1