dee-vee. The best way to tell is to park the bike at the position where you'd normally ride and then sit in a car about 2 blocks back. If the jacket doesn't have some sort of horizontal stripe, the bike may need additional lighting.

[slightly off topic]
I am struggling with front and side vis. Just came in from trying to wrap my handlebars with yellow reflexite tape purchased from this thread. Drivers are used to seeing 2" width. So if I wrap the handlebars, the bike will appear further away. Yes, it looked stupid too.


Here is a thread from last year that may have more links
http://www.bikeforums.net/showthread...ght=reflective