Canada's two biggest railways are phasing out or retrofitting their older DOT-111 tanker cars -- the kind involved in last summer's fiery disaster in Lac-Megantic, Quebec.
CN Rail said it will get rid of the 183 older cars it uses, and CP Rail is upgrading the almost 200 such cars it uses to make them safer.
Although the DOT-111 is considered a workhorse, critics say models built before October of 2011 are not strong enough to remain intact in an accident.
Models constructed after that date are built to tougher safety standards.
Last July, 63 older DOT-111 cars carrying oil derailed in Lac-Megantic.
All but three of those cars were breached and released oil, triggering fiery explosions that killed 47 people and destroyed 40 buildings.