Is pavement crack sealer dangerous?
 

I was out riding the other day on a road I hadn't been on in a while. One part of the road has a sharp curve combined with a shallow downhill. As I entered the curve at around 20 MPH, I discovered that the road had been painted almost edge-to-edge with a spiderweb of that rubbery tar-like stuff they use to cover cracks in the asphalt. Probably something similar to this stuff. Almost immediately I could feel my tires start to squirm around like they were about to skid. Thankfully I was able to stay in control, but, as I've had incidents like this several times over the years, I'm wondering if this stuff is really as slippery as it feels? Or does it just feel squirmy because it's made mostly of rubber so it kind of stretches a little, but won't let the wheel fully slip sideways?

After one particularly scary incident a few years ago on a really fast downhill, I usually try to avoid rolling over the stuff, but every so often I get caught off guard, like this time. So I'm wondering if anyone else has had problems with this stuff on the roads.

I've never noticed it to be slippery, but can't say that I've ever dealt with it on a descent or paid much attention to it. Maybe I should.

Not slippery, but gooey. It's only an issue if you happen to be travelling in the direction of the stuff, and if it's a wider/straighter patch, and only if it's really hot out.

Pavement seams without it are even more dangerous. My right thumb will never have full ROM again... :(

I'm going to say in the rain, it will get you sideways under hard braking. Haven't had any issues with it on dry pavement. They usually sand it if they are doing a larger patch.

Motorcyclists call them "tar snakes" and consider them dangerous. Surely they affect pedal cyclists too, and I've felt my bike squirm a tiny bit on 'em but never dangerously.

Until now, I've not heard of other cyclists having issues with them either. Maybe it's not as bad for us because of the lower speed and narrower tires?

I've felt what seems like a bit of squirm on them a few times. Just enough that I'd be a little more cautious if I encountered them in a turn.

I was on a group ride the other day and some had been added to the route from the previous year. It caught me off guard, I could see it taking someone down had ir been a little more aggressive.

I think they drill out the asphalt before filling like a dentist so there's enough channel to catch a narrower tire.

They are slippery when wet, for sure!

On dry pavement I've only noticed a problem once, like you on a descent. It was humid so there may have been moisture on the road, or maybe petroleum separating out. Going >30 mph on a curve, rear wheel slid (jerked) probably an inch or two, though it felt like more. Bike immediately straightened out without me doing anything. Quite the adrenaline rush.

On wet roads, sure, the crack sealing "snakes" are definitely slippery.

Pavement sealant can be dangerous if you're not paying attention, or going too fast to react. But, so can many, many other road hazards. Just another thing to which attention must be paid.

Two words: "Joseba Beloki".


I hit a patch of fresh crack sealer yesterday (may have just been put on that day) while going around a corner in my car. Back end of the car slid about a foot. This was not the gooey type, it had a lot of sand in it.. But still very slippery. Had I been on my bike I might have gone down.

That sealant is definitely slippery when wet.

I had my bike wash out on me once after a light rain, on a mild curve, under gentle braking.

I think I was running a GP4000 tire, not the poorer-traction Gatorskin.

In this case it wasn't super hot (about 80F), but the sun had been strong all day, so the pavement had plenty of time to heat up by the time I got there around 2PM. There were lines of it crisscrossing all over the place so I'm sure I was hitting some of it parallel to my direction of travel. It also looked fairly fresh and not sanded. I've gone over more weathered and hardened sealer and it usually feels a lot less slippery.

Good info. I did a quick search on "tar snakes" and there's plenty of discussion about them in the motorcycle community.

I found one discussion (having trouble posting the link) where the consensus seemed to be that they aren't as dangerous as they look/feel, but still can take you down if you're too aggressive or panic and react badly. Of course the traction and dynamics are somewhat different on a bicycle, so who knows how applicable this is.

I crashed hard in Missouri on a road crack. Hyperextended an elbow which took a long time to heal.

Crack near a drain in Portland gave a quick pinch flat, and perhaps damaged the wheel.

I think one of the problems with the cracks is that when water gets in, it erodes the soil under the roadbed, and makes the cracks expand.

So, yes, seal them.

We've got a few local cracks that took a lot of sealant, but it is much safer now.

Slippery when wet as others talked about is probably an issue. Ride safe and with caution.

HOT TAR is also an issue in some places, although not necessarily crack sealant.

Crossing the town line at 0:13, and first town doesn’t crack seal so it’s thread the potholes, second town does crack seal.

Yes they are very slippery when wet, yes they can down a person on a bike or bicycle. See 0:15. Spoiler alert - I did not crash.


-mr. bill

Mostly around here they just use an air hose to blow out the dirt & loose chunks and dry it a bit before filling.

I ridden on some that run the in the same direction I was travelling and felt the bicycle really squirm. I think it depends on how deep the crack was, how much sealant was used, the temperature on the day you hit the sealant and finally how far above the road surface is the sealant strip.

Cheers

Similar experience to many that posted before.

Just one of the many things to watch out for when riding, with the heat wave right now that stuff is seriously gooey!

probably not a bad idea to avoid it just to keep your down tube from getting covered in crack sealant.

When i worked on the road dept during college the stuff was called synthetic mastic. Very nasty to work with!!!