I have lived and worked in

[greekfire]

I have lived and worked in Carlsbad for 5 years and don’t have first-hand experience about the commute from Temecula to Carlsbad and back again. However, I do know that the I-78 can get a crowded in the morning going east and in the evening going west. Depending on which part of Carlsbad you plan to work, you’re probably looking at a 1-hour + commute time each way:
Google Map

Here’s the CalTrans site on local traffic: http://www.dot.ca.gov/dist11/d11tmc/sdmap/showmap.php

Check it out to get a feel for local traffic conditions.