Best Route to Cape Cod
GSP to Tappen Zee to Merritt to Middletown CT (rt 66?) to RT 9 (Wilbur Cross) to 95 to 195 to 25 to 6
Or GSP to GWB to HH to Merritt.
287 to 87 to 90 to 495 to 25 to 6.
It's due north, but it avoids traffic in NY and Ct.
Depends on the time of day and day of week.
Weekends I like the GWB to 87 to Cross West Chester to Hutch to 287 to 95 to 195 and as above.
Avoiding GWB, GSP to 287 to 95 to 195 and as above.
I find all 90, and 15 and 66 to be to much out of the way.
90 is out of the way, but it is clear of traffic and quick, gets you to 495, which gets you to the Cape, if you go during the week.
Not sure why you need to avoid the Cross Bronx (I-95). At times when traffic on it is bad, traffic on other routes is also bad. The alternative to the GWB is that Tappan Zee, which is a longer route and not necessarily less traffic. You can take the GWB and then avoid the Cross Bronx by the Henry Hudson/Cross County/Hutchinson/Merritt route, but that is not better either depending on time of day.
The best advice is to leave early, arriving at the GWB before 7:00 AM, then just take 95 all the way until 195 in Providence and then 25 and 6.
If you must travel in the late morning or afternoon, there is just no good option. There are only 3 highways into southeastern CT (95, Merritt, and 84), and all of them are a standstill going east/north for most of the day. Just go very early in the morning is my advice.
if you don't mind a creeping parking lot all the way to RI, go ahead!
The last time I drove to the Cape, I left at 2 PM on a Friday and it took me something like 9 hours. Go when there is no traffic. Connecticut sucks.
GSP to TZ to 287 to Hutch/15 then cut down to 95 (rt.1, etc.) as you see fit, to 195, etc. If GWB is free go for it, but get up to be Hutch somehow when in NY.
Full disclosure: I love the Merritt, but it helps to (ahem) DRIVE it.
ETA: And what others said about leaving VERY wary or VERY late. And never on a Friday if you can avoid it.
Rarely. Only with construction (that I can work around in advance on Rt.1 or wherever, though if it's bad it's BAD) and maybe around New London/Groton. I'll be heading to Providence next week and can do it in just over 3 hrs, effectively the same route until you cut up.
At most times on most days, the GWB is a better option than the TZB to reach coastal New England. You can get stuck in the Bronx for 15 or 20 minutes, and it is still faster. Often, the traffic in Connecticut is the bigger gate to speed.
Avoiding the Cross Bronx