I5 has a fair amount of commercial traffic but nothing like 99. Last time down 99 the commercial traffic outnumbered the cars with lots of slow trucks entering and exiting due to all of the town and business hauling. Not possible to cruise in the right lane and lots of moving left when clear to go around trucks at 45mph. I5 may be dull but I spend most of the time at a steady speed and not dodging trucks. Being from SoCal I would be happy if Sacramento and Bakersfield were twin cities as there is little between the two I find a need for.