I use Hardy Toll to avoid 45 North traffic even at midnight!!!

Depends where you stay but I would say wherever you stay the worst times during the weekdays are 7:30 am-9:30 am and 4:30-6:30 pm. You might have traffic around lunchtime too if you stay in a place with a lot going on. For reference I stay in Cypress and frequently drive around Cypress, Jersey Village and Acres Homes area during the week.