Here's an important pdf, Who's in Danger Race, Poverty and Chemical Disasters. It talks about the "fenceline zone" of danger, its impacts felt 5 miles away. If you live along a rail that will be carrying crude, you need to ask the following, from page 49:

"Shelter in Place" Won't Protect Us
Companies that use extremely hazardous chemicals often tell people that live, work, or go to school nearby to "shelter in place" during a toxic cloud emergency. That means go indoors and close doors, windows, and vents, and wait for toxic fumes to blow away. A simple timeline illustrates that sheltering will not protect numerous nearby people at risk:

[1] How long will it take (in minutes) for:

the company to find a chemical leak?..................______ (min.)
the company to decide to report the leak?............______
the company to notify the fire department?............______
the fire chief to arrive on-scene?........................______
the fire chief to order protective action?...............______
emergency responders to notify the public?............______
workers and neighbors to shelter or evacuate?...... ______
all of these events added together?..................... ______
[2] How long will it take (in minutes) for:

a toxic cloud to reach nearby houses, schools, libraries, offices, malls, sports arenas, or hospitals?............ ______ (min.)
toxic gases to filter into places where people shelter in place? _____
the company to stop the chemical leak?......................... ______
[3] Given these estimates, how big is the "near zone" where neither sheltering nor evacuation will protect people in a major release? ______ (miles)

And, if shelter in place won't work, by when and how will the company reduce or eliminate the chemical hazard at the source? ______ (date)
[1] How long will it take (in minutes) for:
the company to find a chemical leak?..................______ (min.)the company to decide to report the leak?............______ the company to notify the fire department?............______ the fire chief to arrive on-scene?........................______ the fire chief to order protective action?...............______ emergency responders to notify the public?............______ workers and neighbors to shelter or evacuate?...... ______ all of these events added together?..................... ______[2] How long will it take (in minutes) for:
a toxic cloud to reach nearby houses, schools, libraries, offices, malls, sports arenas, or hospitals?............ ______ (min.)toxic gases to filter into places where people shelter in place? _____ the company to stop the chemical leak?......................... ______[3] Given these estimates, how big is the "near zone" where neither sheltering nor evacuation will protect people in a major release? ______ (miles)
And, if shelter in place won't work, by when and how will the company reduce or eliminate the chemical hazard at the source? ______ (date)