I-4 is a different level of crazy during the morning commute in the downtown Orlando area. I missed an exit and had no choice but to go that way on one of my trips to Disney in March. I don’t know the area well enough to know an escape route. I have been on it a few other times because I had no choice and it wasn’t any different than I-75. Very busy, but not a parking lot. I’ve never traveled between Disney and Tampa on I-4, but I suppose it’s probably similar.
I will say that traffic on all the roads can be brutal. Mornings are usually okay when we venture to Disney, but when we return, 95% of the time we finish our day in stop and go traffic. My last Costco run using I-75 dealt with a burning car on the return trip. Originally, the trip was going to be 3 hours rather than the actual 1.5 hours. Traffic did clear. It only was 30 minutes extra. The alternate routes given by the gps turned out to be 3 hours so I was glad I stayed on I-75.
DH had to pick me up from Sanford and he watched on Google maps for a week to find the best route (boredom set in while I was gone I guess

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I know when we closed on our house in Jan 2021 we were going to Sanford and it should have been 1.5 hours, but there was an accident on I-75 right before the turnpike and the gps had it at 3+ hours.
Give yourself lots of time for the return trip. So many people moved to Florida and there are a lot of visitors who are driving. I’ve looked at a lot of plates sitting in traffic. When DH flew out of MCO, we doubled our time to the airport for departure and when we have flown together in the afternoon, we’ve gone to Springs and then left from there so we are closer.
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Every trip there are several cars that zip in and out of traffic at very high speeds. I’m referring to the comments about Chicago traffic. I drove that for 4 years into downtown Chicago. It’s difficult to zip in and out of traffic going into downtown Chicago because “from the Super Target on the right” it was always a solid parking lot. I don’t miss that traffic. At least here, I have a better ending, both ways. We found that level of insanity along our entire route on major highways/freeways/tollways. I guess those drivers didn’t take physics.