Hong Kong's new electronic auto-toll system was on Sunday extended to the Lion Rock Tunnel, which connects Sha Tin and Kowloon Tong.
HKeToll eliminates the need for drivers to stop at booths to pay tunnel fees, with the tolls automatically deducted for those with a registered electronic tag in their vehicle.
While the roll-out at Lion Rock was mostly smooth, some drivers still slowed down or stopped at the old toll booths and needed guidance from tunnel staff.
"It's the first day for the system to be used at this tunnel and the traffic signs are not clear enough. Arrangements on the first day are always chaotic," a taxi driver said.
Another motorist told RTHK that he was already used to the system, having tried it at the Shing Mun Tunnels and the Tsing Sha Highway where it was launched earlier.
Transport Commissioner Rosanna Law previously said that she doesn't expect the system to significantly relieve traffic jams at the Lion Rock Tunnel, although the traffic could move quicker.
The government has yet to decide when to extend the e-toll system to the three cross-harbour tunnels.