Drivers of the now-ubiquitous go-karts reminiscent of Nintendo Co.'s "Mario Kart" video games will soon be required to buckle up for their safety.

The government is working on a revision to the rules of the road for the drivers, who are mostly foreign tourists, which will require them to fasten safety belts over their costumes.

Taking into account a recent spike in the number of users and a spate of accidents resulting in injury over the last year, the transport ministry has decided to revise the Road Transport Vehicle Act by next March, with a view toward strengthening safety regulations for go-karts.

The services, which let tourists dressed as Mario and other characters from the popular video game cruise the often-congested streets of the capital in the low-riding vehicles, have been tremendously popular among foreign visitors to Tokyo.

The decision was made amid growing concerns over a traffic loophole that has permitted go-kart drivers to ply the streets without seatbelts and helmets. Go-karts, under the Transport Vehicle Act, are classified as scooters, the drivers of which are not required to wear seat belts. They are also categorized as four-wheel cars under the Road Traffic Law, allowing drivers to cruise roads without helmets.

The ministry is also planing to introduce a number of other safety requirements for drivers. These will include the setting up of rear-view mirrors at least 1 meter from the ground and a backlight at the highest point of the vehicle, a headrest requirement, the use of soft materials for the handle and the addition of a fender to prevent clothes from being caught in wheels.