Use the parallel street, and give the drivers in a hurry one more reason not to cut through a residential street at a high speed. I live on a street like this- about 3 car-widths wide, usually cars parked on both sides, so one clear lane up the middle. Anything that slows the traffic down and reduces the too-fast cut-throughs is fine by me- and probably is as well to the homeowners/residents on your parallel route.