Slippery paint lines can cause a fall

Time for a new helmet after this one served its purpose.

Time for a new helmet after this one served its purpose.


While we all know rain, painted lines and bicycles don’t mix, I found out the hard way on Sunday during a ride.

I’m not the most aware person, as Jobst Brandt once showed me on a ride up Page Mill Road. He said, “Watch out for the black ice.” Two seconds later I was down.

Jobst never let me forget that. So I probably had it coming when I fell on the paint lines on Tantau Avenue in Cupertino next to the fabulous new Apple headquarters under construction.

It was the perfect mix of wetness and bad luck as I moved left to enter a left turn lane at Pruneridge. Both wheels must have been on the bike lane as I looked back.

The bike went out from under me in an instant. Then I got a ride to the same hospital where Jobst once stayed after his fateful accident in 2011.

I won’t say the helmet saved my life, but you won’t see me riding without one. I’ve had too many incidents — broken cranks, slippery roads.

After checking the paint lines, I think they’re old enough to have been put down before better paint-grit combinations came along.

As for the green paint swathes, I think they’re safer when wet because they have grit in them, or they conform better to the pavement. They’re an issue in Australia though.

The slippery white lines were a problem in Portland, Oregon, and had to be re-striped.

Finally, if you’re seriously hurt by a white paint line, there’s always someone willing to represent you in court.

Follow-up: After talking with the eyewitness and carefully reviewing the scene of the accident, here’s what happened. I was riding southbound on Tantau in the bike lane prior to moving left to turn onto Pruneridge. At the location I was observed falling there are patches of green paint designating a bike lane. These have become worn from constant sweeping by a street sweeper assigned to keep dust down where the Apple campus is being built. The combination of light rain, dust and finely polished green paint made this surface an extreme hazard.

I reported the accident to the city of Cupertino via email and letter.

After this incident, I believe the green paint swathes constitute a hazard once they become worn. Not good.

Follow-up 2: I took my wheel and some water to test my theory about the slippery green paint. After testing, I found the issue to most likely be one of a slurry of mud accumulating on a white paint line, not green.

The green paint is a lot like sandpaper in consistency. Although it loses some traction when worn, it didn’t seem any worse than regular pavement.

However, the white lines definitely had less traction when wet, especially with a slurry of mud, which you can see below. A thin layer of mud is deadly for bike wheels. Because this street is in a construction area, there’s a lot of dust being generated. Sweeping helps, but there’s still a layer of fine dust.

I also tested some concrete next to the curb. Surprisingly, even when wet it seemed to have better traction compared to the white paint line. It may be that sweeper does a better job of removing dust from concrete compared to the white paint.

Conclusion:
My front wheel went out from under me on a white “paint” section, not green, although I can’t say for sure since I don’t know the precise location.

Wet mud on this white arrow can cause a fall .

Wet mud on this white arrow can cause a fall .

8 Responses to “Slippery paint lines can cause a fall”

  1. Jon Spangler Says:

    Did you suffer any injuries, Ray? Road rash, concussion?

  2. ted Says:

    hope you are okay……back on your wheels again soon!

    how do you feel l about riding in the rain over all Ray?
    Do you do that often? Long rides? Also, how about Jobst and the rain…..did he not ride as much in the winter…..go somewhere dry….or did he like riding in the rain?

  3. Ray Hosler Says:

    Concussion. Jobst was never one who rode in the rain, intentionally, except in Europe where it’s a necessary evil. He also rode in snow, on frozen lakes.

  4. AlphaRoaming Says:

    I find those green swaths on Tantau to be annoyingly bumpy. I have been known to “take the lane” to avoid them on a fast descent.

  5. Ray Hosler Says:

    Alpha: Yes, they’ve been chewed up by the construction. All I can say about any kind of paint is that there must be formulations that are more favorable to bike tires, although the lesson learned is to treat any wet, painted surface with a healthy dose of caution.

  6. Grego Says:

    Heal well & be well, Ray.

  7. Bill Says:

    Best wishes Ray and may the adventures continue.

  8. robert Says:

    The mud/dirt from the new excavations on Tantau have been tracked into the street by the dump trucks. The slipperyness is all from that dirt getting wet. Rain on Tantau was not a problem until we had the dirt, too. There is still a lot of dust out there. I am not looking forward to the next storm. You should definitely send your bills to Apple.

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