Congestion and queuing is reduced as traffic continues to flow steadily and the risk of collisions from vehicles approaching the back of queues is lessened.
Bydd llai o dagfeydd a llai o giwio wrth i draffig barhau i lifo yn gyson, ac mae’r risg o ddamweiniau wrth i gerbydau agosáu at gefn ciw yn llai tebygol.