The ride on the coastline from the beach areas to the city takes too long on a local train and unless if there is a lot of traffic, the train doesn't work well with people's schedules. Most of the people who take the train from the south end of the Coastline are either commuters heading to NWK or NYC or your vacation travelers wanting to head from NYC, NWK, or other stops to go to the beach either on a Friday later in the day or Saturday in the morning and then they come back up in the late afternoon to early evening on a weekend. There are many people who live very close to the south end of the Coastline who prefer to drive up the Parkway or Rt. 9 to Metropark for faster and more frequent service. There are probably many people who might drive to Aberdeen-Matawan as well. The proposed preferred MOM routing by NJT, which isn't really my favorite, takes way too long. The problem is not the NEC but once the trains travel on Conrail's Shared Assets. I have never traveled on Rt. 9 south of Sayreville during rush hour but I am not too surprised that there is a lot of traffic. I noticed that NJT runs various zone bus expresses which helps with the travel time and crowding. If I was head of NJT, I would say either build the route through Matawan, Marlboro, and Freehold or don't build it at all.
As for the Rt , Turnpike, and 130 corridor, the improvements should be focused on the NEC for the most part. It's very important that the station in North Brunswick near the old Johnson & Johnson site gets built as well as the yard there. It's way too long of a gap for a stop for NJT between Jersey Avenue and Princeton Jct. In fact, I would probably say move County Yard to N. Brunswick as there is more room. I believe there is a plan to build a loop at the proposed yard which would probably help trains not tie up all of the mains which happens at County yard and interlocking. Getting to the Jamesburg Branch-I had this suggestion before to maybe build a park n ride lot near where the NJ Turnpike goes over the Jamesburg Branch and run some rush hour trains there. It's important at the very least that the station and yard get built in N. Brunswick and that would be beneficial if you live in S. Brunswick, Monroe Twp, and Jamesburg because it would be a matter of heading up 130 a few miles rather than heading into Downtown New Brunswick. Jersey Avenue station could and, in fact, should have high level platforms on both sides of the NEC.