KUALA LUMPUR, Aug. 28 -- Giving way to emergency vehicles is one of the first traffic rules we learn, long before we get behind the wheel.

But while sirens and flashing beacons signal that other road users should make way, they do not mean these vehicles are automatically exempt from traffic laws.

A fatal crash on Jalan Sultan Ismail on August 19 brings the issue under renewed scrutiny after an Immigration Department truck allegedly went through a red light, collided with a Proton Saga and then struck four pedestrians, killing three.

The 43-year-old driver was reportedly on his way to pick up undocumented migrants detained in a raid, with the truck's siren and beacon light activated at the time.

He has since been charged under Section...