YES, they do if you have the right front flasher.
I run a front Cygolite Metro 400, (the daylighting lightning flash gives a 500 lumen strobe), and a rear Cygolite Hotshot.
I have been told many times that I am seen and cars really react and give me a lot of room.
I also wear a yellow hi-viz vest which helps.
Yesterday I had 3 different cars pass me (with a lot of room) and gave me a wave and a thumbs up.
Me thinks this a good sign.