Should freight trains filled with potentially explosive goods be freighted through some of this country's most densely populated cities?

That's the question one Toronto city councillor hopes will prompt further changes to rules around the transport of dangerous goods by rail in Canada after the federal government announced new measures that would cut in half the speed limits for trains carrying such goods.

The changes came just days after a train carrying crude oil derailed in Saskatchewan, bursting into flames and forcing people to evacuate their homes. But while Coun. Josh Matlow says he welcomes the new speed rules, much more needs to be done.

"We wouldn't expect that any car company wouldn't recall a typical vehicle on our roads. Why would we expect anything less by cars that are carrying dangerous materials?"

The new federal order, which took effect Friday at midnight, will require trains travelling through metropolitan areas to limit their speed to a maximum of 32 km/h, and 40 km/h everywhere else. Before the order, trains were required to limit their speed to 64km/h in metropolitan areas, and 80 km/h everywhere else.

String of derailments in Toronto

But it isn't just speed that needs to be addressed, says Matlow.

Toronto has seen its share of derailment scares over the past several years.

In 2016, two Canadian Pacific trains collided at a rail crossover near Howland Avenue and Dupont Street, spilling about 2,500 litres of diesel fuel near a residential midtown neighbourhood.

Toronto city councillor Josh Matlow hopes the federal government will beef up its rules around the transport of dangerous goods by rail in Canada after announced new measures that would cut in half the speed limits for trains carrying such goods. (Angelina King/CBC)

A year later, there was another derailment in the same spot. No one was injured.

Then, in November 2018, five cars of a freight train carrying an industrial chemical derailed in Scarborough. No one was hurt in that incident either and nothing harmful leaked.

And of course there was the Mississauga train derailment of 1979 when a tanker car carrying propane exploded, forcing 240,000 people to flee their homes and sending a massive fireball into the sky. One of the tankers in that incident had been carrying chlorine, which — if it had ruptured — could have easily been deadly for nearby residents.

But many residents worry it's just a matter of time before disaster hits, says Matlow.

"Within half a mile either side of the tracks that go through the heart of Toronto an explosion could be catastrophic," he said.

New exhibit honours 40th anniversary of Canada's largest peacetime evacuation 6:00

Among the measures Matlow wants to see implemented are transparency around exactly what hazardous materials might be being transported and how much and getting rid of the remaining DOT-111 tank cars involved in the deadly rail disaster in Lac-Mégantic, Que. in 2013.

The federal government moved to phase out the cars beginning in 2016, and said in a statement to CBC News that it has accelerated the timeline to remove them twice in recent years.

It has also increased the number of dangerous goods and rails safety inspectors, and increased the number of inspections and directed railways to provide municipalities and first responders with more dangerous goods information among other measures among other measures.

Two Canadian Pacific trains collided in Toronto in August 2016, causing cars to derail. One of the train's engines leaked diesel fuel. (CBC)

"Minister Garneau is concerned about the safety of railway operation and has put the Ministerial Order in place as a precautionary measure. He has instructed Transport Canada officials to examine all issues related to this and past accidents to determine if additional safety measures are required," the statement from Transport Canada said.

"We are continuously looking at ways to make further improvements and will not hesitate to take immediate action if necessary to protect Canadians."

In Ontario, CP and CN lines are shared with the provincial transit agency Metrolinx. Spokesperson Anne Marie Aikins says the new speed rules for trains carrying dangerous goods haven't affected transit service yet but that the situation is being monitored.

Aikins says it's difficult to predict disruptions to service because Metrolinx doesn't know which of the cars are carrying dangerous goods.

The new speed reductions are in place for 30 days. That timeframe could change as the government looks at similarities between different derailments to see if even more safety precautions need to be implemented.