Traffic coming into Singapore was heavy on Saturday at both the Tuas and Woodlands checkpoints, while traffic into Johor was light.
Land Transport Authority webcams show a line of cars at the two checkpoints queuing to get into Singapore. The authority's hotline service also reported that Singapore-bound traffic at Tuas was "heavily congested".
Traffic has been heavy on the Causeway since news broke on Tuesday of a Malaysian woman who managed to drive through the Woodlands checkpoint without authorisation.
The Immigration and Checkpoints Authority then stepped up checks, leading to traffic snarls. The incident also coincided with the Chinese New Year season, where traffic on both sides tend to be heavier.