Ann Tuck, 
Basic physics dictates that your proposal is not going to accomplish what you intend.  I understand that this information relates to stopping different conveyances at speeds greater than 25 mph; however, the principal remains the same:

According to the National Safety Council:
A lightweight passenger car traveling at 55 miles an hour can stop in about 200 feet in an emergency—under perfect conditions—that is, if tires and brakes are in good condition and the road is dry.
A commercial van or bus will need about 230 feet to stop.
A commercial truck/trailer can stop in about 300 feet—that's the length of a football field.
A light rail train requires about 600 feet to stop—the length of two football fields.
Compared to this, the average freight train we mentioned above traveling at 55 miles an hour may take the length of about 18 football fields to stop.
Trains can't swerve—they can only follow the track. The only thing the engineer can do is apply the emergency brake.