Senior Sergeant Dean Harker said police received multiple reports relating to the 27-year-old man from Timaru who was driving north near Rakaia about 11.50am.
He was allegedly pointing a firearm out of his car window and firing shots.
Police laid spikes on the Selwyn bridge near Telegraph Rd, which brought the vehicle to a standstill.
The man is due to appear in court next week on driving and firearms charges.