Avoiding major cities is a good idea. Worst conditions I've driven I think were around Atlanta at night, and around Dallas - both with lots of construction and not timed well on my part for rush hour by Dallas. Driving narrow lanes with concrete on one side and semi's on the other isn't fun and I'd recommend avoiding it when you can, but with time you will get more comfortable with it when you inevitably run into it.
I must also say that my first long trip pulling a TT many years ago we intended to go around Chicago at noon-time but missed a turn and ended up taking 94 right through. Stop and go traffic for 90mins isn't dangerous but sure is stressful...especially when the gas gauge is starting to blink. I ended up nosing my way across traffic lanes to take a city exit to get gas, of course the gas station was on a pie-angle corner so I had to back in/out and hold up traffic for a minute getting in and out. Can't say I enjoyed the experience (nor did wife and kids), and I sure lost a lot of sweat but I did learn two things from the experience: 1) LOTS more confidence that things will work out and the world won't end if you have to hold up traffic for a minute, and 2) Start looking for gas when tank reads 1/2 and make sure you fill by time it's at 1/4!!
