The way points of this bicycle route:
McMansions to the west, oldfields to the east
Grouser Rd. Nice shady paved road with no traffic. Some nice sloping road to get the muscles warmed
Canal Road, parallel to the Millstone River canal. Very scenic, low traffic smooth paved road. Mostly level.
Bunker Hill Road. Climb bunker hill to get the legs burning. A nice, easy climb with low traffic. Take to Rt 27, turn around and return to Canal Road to continue this trip.
Suydam grasslands. Take off your headphones and listen for Grasshopper Sparrows, Eastern Meadowlarks, Bobolinks, and other grassland species rare in New Jersey
S. Middlebush Lane. Traffic increases, but there's a good shoulder on the east side of the road until Hilltop Rd when it turns into a skinny single-track until you turn off onto Blackwell's Mills Rd (but the downhill is awesome!)
Hilltop Rd! Nice downhill after the climb!
Hutcheson Memorial Forest entrance. Not open to the public except for scheduled tours; more info can be found at hmf.rutgers.edu