A dagger and ball-bearing gun with ammunition were discovered on a man who was driving under the influence.
West Yorkshire Police shared pictures of the weapons which were found in the vehicle after stopping it in Wakefield.
The force's Road Policing Unit tweeted they had stopped the driver and checked him, before arresting him for being over the drug drive limit.
Pictures show the knife, which measures over 40cm, and the black BB gun and jar of BB pellets.
The RPU wrote: "Upon a search these were on his person. Why do you need to carry a knife?"
It comes amidst a surge in knife crime on Britain's streets. Statistics released by the Home Office last month showed a steady increase in the numbers of offences involving knives in England and Wales since 2014.
In a statement last month, West Yorkshire Police & Crime Commissioner Mark Burns-Williamson said: "Our police do an extremely important job in protecting our communities and carrying out robust enforcement against offenders, but it is ultimately through early intervention and prevention work that we can most effectively tackle knife crime and serious violence.