As the night rolls on, eight in ten young cyclists may bike home dangerously tipsy, according to new research.

A study by the traffic safety research institute SWOV suggests that 68% of young cyclists ride home under the influence of alcohol by 1am, rising to 80% by 5am in the morning.

Their average blood alcohol level is 1.0g/l, meaning they are five times more likely to have an accident compared with a sober cyclist, it reports.

The study was carried out in Groningen and The Hague in conjunction with Groningen University. People’s blood alcohol levels were measured on a Thursday and Saturday night between 5pm and 8am in the morning, at the end of November 2013.

More cyclists were likely to be over the legal limit in Groningen (48%) than in The Hague (30%).

A separate study on drinking and driving cars, also in the report, showed that 40% of cars on weekend nights are driven by young men aged from 18 to 24, six in ten of them carrying passengers.

Although young men are slightly more likely to violate the legal alcohol limit and drive (2.3%), this is not significantly higher than the average (1.9%).