Around 200,000 fines have been issued since electronic tolls were introduced for a motorway tunnel in Rotterdam, raising concerns that the gate-free system is catching out unwitting motorists.

One in five drivers initially failed to pay the toll on the A24 that runs under the Maas at Maassluis, connecting the A15 from Rotterdam harbour to the A20. The fee of €1.51 for cars and €9.13 for lorries was introduced in December.

Drivers can pay the toll up to three days after their journey via the online portal e-tol.nl or an affiliated app such as Flitsmeister. Those who fail to pay are sent a reminder by the RDW, but if they still refuse they receive a €35 fine.

Altogether 1.9 million reminders were sent for the 9 million journeys through the tunnel, 90% of which were paid. The 200,000 fines netted the RDW more than €7 million.

After December 7 the first reminder, sent when drivers fail to pay within 72 hours, will come with an administration fee of €9, six times the toll rate for cars. The fine of €35 will be unchanged.

Jan Strijk, director of toll payments at the RDW, said drivers were having to adjust to the electronic system of paying tolls without gates and barriers.

“There are lots of signs in the area, not just at the tunnel but on roads leading towards it,” Strijk said. “If you miss one it’s unfortunate, but the great advantage of this system is that we have a toll road where drivers don’t have to stop.”

The government decided to make the A24 a temporary toll road to make up for a shortfall in its construction costs. The tolls will be removed once the deficit has been made up, which is expected to take around 25 years.