How much safer is a Volt than other cars?

Short answer:  "A lot safer."

Longer answer:  There were 184,500 car fires last year according to the  National Fire Protection Association.  That's one fire for every 1,380 cars on the road ( assuming 254 million cars per various sources including Wikipedia and Hedges Company).  Given about 8,000 Volts on the road today, we would expect 5.8 fires so far based on typical internal combustion engine (ICE) cars.  So if there were even one actual fire in a real collision, the Volt would still be 5.8 times safer than average ICE cars.  But since there have been NO reported fires, the Volt is actually infinitely safer!  5.8 ICE fires divided by zero Volt fires = infinity!