Living in Cincinnati these past 14 years, I avoid I-75 as much as possible. I think you would like the following adjustment to your Northern trek: When you cross the Ohio River take the I-71 exit immediately on the right, stay in the right lane (1/2 mile) and after a short tunnel you are North bound on I-71 towards Columbus. In less than 20 miles, go West on I-275 to hook back up to I-75 North (about 4 miles). This short detour is actually quicker and you don't have to fight the congestion and construction on I-75. By all means try to avoid the 4:00 - 6:00 PM rush hour traffic