do you turn on your front and back lights when you go biking (on the road) during the day?

Yup. Almost always the front, and I'll add the rear if I think there's enough clutter, distractions, and/or shade.

I turn on my car's lights in town, too.

I have two Planet Bike Superflash tail lights, one on the seat post and one on the left seat stay. More often than not, I use them on daylight rides. The front light is a little Cateye to-be-seen light which has a flash mode. I'll use it on my evening after-work rides.

Front yes, rear no. From my observations, bikes with bright lights on during the day really stand out and would have less of a chance of being overlooked by a car. Most rear lights are worthless during the day. A high-vis vest/jacket provides better conspicuity.

Yup, I turn em both on... although i whole heartedly agree the rear is next to useless, which is why i'm currently working on that

Yep, Planet Superflash on helmet and a Blackburn Quadrant on front in blink...My MR16s and Zenon strobe are just when it's dark or raining....

Nope. Because unless you want to run lights like these all the time, most bike lights are just too weak to be seen in full daylight. That's front and rear.

Running lights on an automobile makes some sense since they are larger, have more light output, come in pairs and are set roughly 4.5 feet apart. On bikes? Not so much. I rode home with someone last week who had her flasher going. It too me twenty minutes to notice that she had the light going under the saddle.

Yes, Dinotte 600L on the front, Dinotte tail light on the back rack, PB SuperFlash on the helmet back -- all in full bright strobe mode. The Dinottes are both very visible in daylight, the SuperFlash not so much.

I have an amber Dinotte 200L that I run in flash mode in the daytime. I also run a Blackburn Mars 2.0 flashing also because it's fairly large and I figure that size matters more than brightness in the daytime.

I tend to use lights when conditions are not so good : black clouds, rising or setting sun, etc. From following other riders, I can tell that the average rear flasher is easily noticed.

As for Cyccommute, I suspect you might have been too close to really notice the light or the batteries were really weak. Typical LED lights have two flaws:
– they are highly directional, yet many people install them pointing anywhere except where they should;
– they gradually dim over time, so after 25-50 hours of riding, one should get new batteries; yet, many people seem to replace batteries every 4-5 years... if they think about it.

Depends on the conditions. If it's a bright bluebird day then no, for whatever light I'm running will be washed out and not seen. On dark overcast conditions though then yes..

Actually, if the day is bright, I think that my amber Dinotte can be seen pretty well. Sunlight reflections from parked cars have about the same color as white LED lights, but the amber is different enough that it should stand out fairly well.

Seconded on the Dinotte amber: people do notice it. Except people who just don't look, of course, but a loud expletive usually sees to that.

I run the Dinotte rear as well. Never used to bother running anything at all, until I noticed other cyclists were more conspicuous with them. Aside from the Dinotte, the Superflash is the best I've seen. That said, I don't spot dark clothes and a typical rear light during the day as quickly as I do a high-vis and no light.

And as Dinottes aren't cheap, it's nice to get your money's worth out of them...