it's definitely possible! i bike through downtown and the hill pretty regularly and often cross the blvd into west haven using rte 1 -- these are among the busiest roads in the area, but i have never had an issue using them. you can also ride through westville and take marginal drive into west haven to avoid rte 1 -- that might be the safest and easiest bike route available. i would definitely avoid riding on the boulevard itself.

that being said, there are alternatives available to biking -- you can take the bus from downtown or even the ride metro north to west haven station and bike from there.