I have used Lake Mary Blvd for over 20 years, before it was four laned, driving it at least 20 times a week and have never had a reason to not use it. A few times I have been stopped by the train and once by construction, but never by traffic jams. There are about 5 stop lights to contend with. Going north on 417 to avoid traffic is crazy. You go north until the exit by the shopping center, go up to 46 west on 46 underneath I-4 and than take the exit to Orlando. You will run into more traffic going that way than if you went straight out Lake Mary Blvd to I-4.