Be aware of the heavy commercial truck traffic along 99 compared to the I-5. Some slow and then some fast but most behave themselves, just lots of traffic. Compared to I-5 which is all 2 lane from the 99 split up to the 205 south of Stockton much of 99 is 3 lane but it comes and goes with no real reason, some 3 for a while and then back to 2. With all of the towns along 99 there are many places to stop for a rest, the shopping center at The Lakes RV park exit is large and easy to use. Enjoy the trip.