Nearly 8,000 people were arrested for drug-driving in England and Wales in the last year, new data shows.
The statistics come after regulations were introduced last year to crack down on motorists who drive under the influence of drugs.
According to figures obtained through Freedom of Information requests by BBC Radio 5 Live, 7,796 people were arrested on suspicion of drug driving between March 2015 and April this year.
Data was supplied by 35 out of 43 police forces.
The Metropolitan Police made the most arrests, 1,636. The capital's force was followed by Greater Manchester Police with 573, and Cheshire Police with 546.
Drivers can be prosecuted if they are caught exceeding limits which were laid down for eight illegal drugs and eight prescription drugs.
The levels for the illegal drugs, which include heroin, cocaine and cannabis, virtually mean there is zero tolerance for drivers caught with these substances in their system.
With the introduction of the new law, police were issued with testing kits.
Officers can use use "drugalysers" to screen for cannabis and cocaine at the roadside and they can test for these and other drugs including ecstasy, LSD, ketamine and heroin at a police station, even if a driver passes the roadside check.
The legislation was introduced to run in conjunction with a previously existing law which made it illegal to drive when impaired by any drug.
For some forces the introduction of the test and the legislation has had a huge impact on the number of arrests.
South Yorkshire Police drug driving-related arrests went from 13 in the year the test was introduced to 456 the following year.
Gloucestershire chief constable Suzette Davenport, the roads policing lead for the National Police Chiefs' Council, told the BBC: "The drug testing kit and the legislation are immensely helpful and have provided the operational officer with the tools necessary to help catch those who take the risk of drug-driving.
"People who previously got away with driving under the influence of controlled drugs are now being detected and prosecuted."