The drive home can be especially difficult when it is always part of your daily routine to stop and drink/pick up alcohol. It takes time for your mind/body to realize that stopping is no longer part of the routine, and that it is just fine for that to be the case. I also lived in your city for five years and it is an especially difficult place to get sober in.
But it DOES get better. Today is Day 100 for me, and I can tell you in all sincerity that it does get better. Every once in a while I'll still get slammed by a big craving on the way home, but now it is the exception and not the rule. But by that time you have have gained the strength to know it will pass and it becomes easier to fight (as long as you keep in mind that you DO have to keep fighting when it comes up).