Some blinking lights are bright enough to be seen very well, and to catch drivers' attention during daylight hours. I've been watching them from a car driver's perspective, and some of them definitely seem better than bright colors, more strongly noticeable or conspicuous. They stand out more.

Which lights would be best for this sort of use?

I really like the small Dinotte lithium lights, reviews here:

Tail light: https://www.crazyguyonabike.com/revie...hread_id=41513
Head light: https://www.crazyguyonabike.com/revie...hread_id=41514

The tail light is particularly impressive - I once had a car driver get out of his car at a traffic light to ask me where I got it, he was so impressed. I'd say it's probably one of the brightest lights out there, hands down - very visible even in daylight. The only thing about them on tour would be that you need to carry the charger for the lithium battery, and of course find somewhere to charge it. There is also an AA version, but I didn't like it as much - the battery holder was not at all water resistant, nor was the connector. The Lithium version lasts longer and seems more weatherproof to me.

Dinotte also makes some larger versions with multiple LEDs - I have one called the 500L, which doesn't seem to be on their website any more, but it is even brighter than the small 140. But I think the small version is probably enough for most uses, and light & small enough to consider taking on tour. One downside I have noticed is that if you leave the battery plugged into the light for any length of time, then the battery becomes drained, so you need to be careful about that. But maybe they've fixed that now - last time I got lights from Dinotte was back in 2007 now. Overall, great lights, highly recommended, especially for commuting. For touring I might just take a battery blinky such as the AAA powered Planet Bike Superflash instead, since it's smaller and lighter and I don't ride that much at night time on tour anyway.

https://www.dinottelighting.com/

All that being said, though, I think that for the best visibility, a bright yellow jacket works better than any light. I've noticed when driving that I notice the flourescent yellow jackets way before any little blinky light.

Neil

Definitely Dinotte... Their 140L tail light is hard to beat, day or night. On the front, I usually run one of the 200L headlights, or a Light & Motion Stella 200N in blinkie mode.

Clothing and road positioning is another way to help increase your conspicuity in daytime. Those hi-vis orange and chartreuse reflective vests are good, and over the past couple of weeks I've been road testing one of those reflective triangle "Slow-Moving Cyclist" warning triangles from Adventure Cycling Assn. So far, I've been pretty impressed with it.

Best? Have no idea. I've been impressed with the Planet Bike Superflash. I don't own one, but have been impressed when I've approached someone from behind during daylight how far off I start seeing it.

I also tend to agree with that crazy guy above that if you are thinking about daytime conspicuity, starting with your clothes is probably a better bet. I like to go with bright yellow.

Speedo

I have a neonlime ANSI reflective striped waterproof- breathable Parka.
This time of year I wear it Daily/ nightly..

If it's good enough for the roadside workers, Its fine by me ..

I've got a Petzl Tikka Xp on the front of my helmet. It has a hi/lo steady mode, a steady/flashing red LED and and a VERY BRIGHT white strobe mode. It also has a diffuser lens that can slide over the LED lens. Set on strobe with the diffuser up a very wide angle strobe is visible from far away. Sometimes I ride with that facing forward during the day when in traffic. At night I'll have the light facing upward so it doesn't blind others but I can see the reflection in signs 100' away. It's a very good strobe light.

Here in sweden by law all cars have their headlights on, day and night... In daylight you never even notice them, so I'm a bit skeptical about the effectiveness of bicycle lights in the day... certainly can't hurt though and blinking lights are possibly a bit better.
I would suggest that neon safety vests are more useful.

edit: actually the headlights do make a difference when seen in a rear mirror and make overtaking safer - especially for motorbikes.

OTOH at dusk you do start noticing car headlights much earlier than most people would consider it getting dark. I put my lights on when I start registering car headlights.

The Radbot 1000 is the same price as a Superflash, is brighter, has a reflector and comes with a rack mount. They also make one for mounting on the rear fender. https://www.ridepdw.com/goods/lights

I went riding with two friends recently. One was wearing a fluorescent yellow/orange vest, the other was wearing street clothes. It was about 11:00 a.m., with sunny skies. We were on rolling country roads, with forests on both sides.

I rode behind about 100 metres. When they rode in shadow, the person wearing street clothes was more or less invisible, while the one wearing the bright jacket was clearly visible.

The best answer might be bright lights AND high-visibility clothing.

Looking at Erick's suggestion Radbot 1000, came upon these quick little comparison videos between it and the Planet Bike superflash, for brightness, Radbot wins hands down.

https://www.youtube.com/watch?v=rg3bg...eature=related

https://www.amazon.com/Portland-Desig...By=addFiveStar