OTTAWA -- Federal transportation safety officials have been urging the government for over a decade to do more to prevent the kind of level-crossing crash that claimed six lives in Ottawa .

Transport Canada and the rail industry have taken steps to improve safety at crossings, but some recommendations remain outstanding, says the Transportation Safety Board, which added the issue to its watchlist of key concerns in August 2010.

"The risk of passenger trains colliding with vehicles remains too high in busy rail corridors," the safety board says in a watchlist notice on its website.

Transport Canada must implement new grade-crossing regulations, develop better standards for certain types of crossing signs, and continue its leadership role in crossing safety assessments, the notice says.

It also calls for more efforts to improve public awareness of the dangers at railway crossings.

"It is something we have been watching," safety board investigator Glen Pilon said Wednesday at the crash site.

From 2003 to 2012, there have been 86 collisions between vehicles and trains at crossings on the busy Windsor-Quebec rail corridor, board figures show.

In the most recent five years, there were 29 collisions -- a decrease from 57 crashes during the previous five years, the safety board says.

"The board acknowledges this improvement but remains concerned that the risk to Canadians persists."

The board urged Transport Canada in 2001 to usher in new regulations that would set clear safety standards for all grade crossings and set out responsibilities related to crossings for railway companies, public road authorities and private road owners.

In March, the safety board said it was "ever mindful of the protracted time this project has taken."

It noted that almost 12 years after the board signalled the urgency of proceeding, and Transport Canada agreed, the draft regulations had yet to be put into effect.

Transport Canada had no immediate comment Wednesday.

A 2007 report by the department said improving safety at level crossings has been complicated over the years by the jurisdictional tangle of federal, provincial and municipal governments.

"While there is some cause for satisfaction, we believe that there is much work to be done to improve safety at crossings. As both rail and road traffic continue to grow, the risk of grade crossing accidents will continue to increase," the report said.

"Jurisdictional disagreements can arise over such issues as lighting, fencing, drainage culverts and maintenance of roads at crossings. An important factor in crossing and trespassing accidents is that they involve and are usually caused by third parties."

The report said that new urban development, with more vehicles on the roads, as well as "the increasing length, frequency and tonnage of trains, the potential for serious grade crossing accidents is growing."