Allamuchy Mountain is the highest point in Allamuchy Mountain State Park, but it has almost no views or steep climbs from the officially maintained trails. The summit consists of rolling ups and downs in open forest with blueberry bushes and lots of sunshine. You cannot see I-80 from anywhere on the mountain, but you can hear it from the summit. The climb from Stuyvesant Road on the Ditch/Cardiac Trail (yes, that's its real name) requires 600' of vertical gain.
Trail Map: NJ DEP map
From Allamuchy Mtn. North, took a few unmarked trails from the summit that went down to a swampy area. Following some unmarked trails I eventually intersected with the purple Cardiac Trail. I took this all the way up until I got close to the summit and then bushwhacked the final stretch to the highest point.