Police stopped more than 800 people in Liverpool city centre in an operation targeting drivers using mobile phones or not wearing seatbelts.
Merseyside police said a "ring of steel" was placed around the city centre with officers on main routes.
A total of 166 vehicles were seized and 49 people arrested for offences including car theft and possession of an offence weapon.
A further 202 people received fixed penalty notices or summons.
Number plates
A total of 59 people received a fixed penalty for failing to wear a seatbelt and four for driving while using a mobile phone.
The operation involved roadside stops and mobile automatic number plate recognition units, ran for 14 hours.
Ch Insp Chris Markey, of Merseyside police, said: "This activity is just one part of our ongoing Total Policing initiative, and we will continue in our efforts to bring those people who flout the law before the courts.
"The co-operation of the public yesterday at out checkpoints was very much appreciated."