A set of R188’s (used on the 7 train) were fitted with rubber tube attachments to dissuade subway surfing.
The MTA should put vertical ones, much like what commuter railroads use as well as someone determined enough may still be able to climb around them. This is a good start though.
BART is another rapid transit agency that uses vertical rubber in addition to the top one. This might also make it safer to walk between cars if necessary as well.
