Relatives of a teenage girl who died after taking drugs on a "party bus" ride applauded changes made Thursday to tighten licensing regulations for limousine operators.

Transportation Minister Todd Stone announced an overhaul of limousine licensing that will require each limousine or bus with to go through its own inspection and hold a licence. This replaces a "general authorization" limousine licence that allowed party bus operators to work anywhere in B.C. and add vehicles to their fleet at any time.

Stone said strict licensing and display of a special plate will allow police to know where party buses are operating so they can be checked. The changes are to take effect by May, before high school graduation events that are a mainstay of the party bus business.

Danielle Raymond and her mother Julie attended the announcement, calling it part of the reforms they have sought since Danielle's sister Shannon died in July 2008 after drinking and then boarding a party bus where she took the street drug ecstasy.

Shannon's death at age 16 was the first in a series of tragedies with party buses, which have expanded to 4,000 vehicles in B.C. Danielle said her own research showed companies advertising open bars on board.

"Basically their whole business operates around facilitating the minors who use them to get hammered, for lack of a better term," she said.

In February 2013, 16-year-old Ernest Azoadam died on a party bus in Surrey. In November of that year, a 17-year-old girl from Abbotsford was dumped at a truck stop an assaulted after a trip on a party bus.

NDP transportation critic George Heyman echoed the Raymonds' suggestion to consider requiring chaperones on party buses to make sure under-age drinking or drug use don't occur. That's part of pending legislation in Washington state, where party buses are allowed to serve alcohol to those old enough to drink.

Heyman said the government should also require safe drop-off locations for the buses, which now drop off passengers at bars and then pick them up later to go to another bar.

"One of the roles of the chaperones would be to ensure that no drinking takes place on party buses, period," he said.