Flashing front light in daytime.

I was stuck in traffic in my car at about 8.30 this morning looking down
at the radio to change channel. Out of my peripheral vision I became
aware of a flashing light from outside. It turned out to be a bike
filtering up the inside, some way back.

I have never thought of using a front light in daylight but was very
impressed by the result. It wasn't the brightest day this morning but it
wasn't really overcast or anything.

I wonder what type of light you need to get these results. Maybe a new
super LED. I couldn't really see what he was using, just a black
cylindrical looking thing.

Maybe I'll be able to ask him another morning. None of you were on
Brownhill road going from Hither Green To Catford at about 8.30 this
morning were you?