Well if skate parks are of any use to you, there's one in Neptune and another in Manasquan. Probably others as well.

The Marshalls & HomeGoods stores in Seaview Square (Rt. 66), Ocean Twp have ramps. And directly behind those there's a sloped driveway (no walkway that I can see) that drops at least 10 feet across 200-300 ft horizontal.

Shark River Hills has lots of sloping roads, especially S. Riverside Dr. Folks walk their dogs there, FWIW.