In this picture of the most used side of yours truly somewhere in the vicinity of Summit Valley MT
you'll notice the topic of today's post: the "rumble strips" cut into the pavement to my right. (Before you reach for the comments key, I'll frankly admit that the Montana DOT intends bicycles to stay on the other side of that strip in the 18" between it and the sand.)
These rumble strips are part of Montana's Vision Zero traffic safety improvement which aims to cut down on highway fatalities (187 last year). On many of the roads we've traveled there are also rumble strips on the center line. The idea, of course, is to alert drivers that they are departing from their lane, even when its intentional. That is, a center line rumble strip is present even in passing zones where crossing the center line is allowed.
For a bicycle the rumble strip is a pounding romp that threatens to shake everything not well secured off your frame, i.e. riding on them is to be avoided whenever possible. On some roads (those designated as bicycle thoroughfares) Montana designs the shoulder strip with the bicycle in mind by putting in a 13 foot gap every 47 feet to allow a place to cross the bumpy barrier. That one gets my endorsement! The other ways across the strip are to make a quick short turn to minimize the time over it, or to "bunny hop" it by jumping both wheels off the ground at the same time while moving sideways. But that's just for show offs, eh hem.
There is no question that our safety is enhanced by having these strips there. One of the most worrisome things to cyclists is an inattentive driver drifting to the right while they check their cell phone. I think its safe to say that many, perhaps the majority, of us have caught ourselves in such a position while driving. That's why PACTour encourages riders to keep a bright tail light flashing at all times - since you can be seen from farther away the chances are greater that the inattentive driver will glance up at the road when you are visible and snap out of their revere.
One of the problems with the strips is that they are effective at keeping traffic off the shoulder. What that means is the useful service that large vehicles provide of sweeping the roadway of sand, rocks, glass and debris isn't provided for us lightweights. The rumble strip budget evidently didn't include street sweepers, so the shoulder can become dicey to ride on. That's why you'll find riders like me making a trade off between risk of cars vs risk of flat tires and loss of traction in making a decision to ride on the roadway side of the strip. Besides the quality and quantity of the shoulder, factors in the risk assessment include high vs low traffic and speed of the bike. Different riders use differing weights (AKA coefficients - you remember algebra don't you?) so come to differing decisions about where to ride. I think its safe to say that everyone agrees when you are being passed by a number of vehicles and there is oncoming traffic, you move over as far to the right as you can.
The other quality of rumble strips that wasn't accounted for by the State is visibility. Naturally when the grooves are first ground out of the tarmac, its obvious that its there, as you can see from the picture above. However the cheap way to maintain roads is to "chip seal" them, which is to spray a layer of oil over the whole road, then spread small gravel on that wet oil, then optionally spray another layer of oil. Do that to a road with rumble strips and you create "invisible rumbles" like in this picture from today's ride looking toward our destination of Bozeman (at the foot of the distant mountains):
Yes, there is a rumble strip there, still quite effective at shaking the bejeebers out of you when you discover it tactilely.
OK, 'nuf of that. Today we crossed the continental divide. So long, Pacific Ocean! The sign at the divide was stolen, so we've got the crest trail sign
and Susan N perched to catch a picture of each rider as they crested the divide for the PACTour flikr album.
Here are some more photos from the Big Sky Country between Butte and Bozeman.
A quaint homestead that I wouldn't live in
The long long road
They got a Madison County here too:
While we booked it down the Madison River gorge John S still managed to check how the water is with the rafters.
A size large flower pot
The musical horse
These rumble strips are part of Montana's Vision Zero traffic safety improvement which aims to cut down on highway fatalities (187 last year). On many of the roads we've traveled there are also rumble strips on the center line. The idea, of course, is to alert drivers that they are departing from their lane, even when its intentional. That is, a center line rumble strip is present even in passing zones where crossing the center line is allowed.
For a bicycle the rumble strip is a pounding romp that threatens to shake everything not well secured off your frame, i.e. riding on them is to be avoided whenever possible. On some roads (those designated as bicycle thoroughfares) Montana designs the shoulder strip with the bicycle in mind by putting in a 13 foot gap every 47 feet to allow a place to cross the bumpy barrier. That one gets my endorsement! The other ways across the strip are to make a quick short turn to minimize the time over it, or to "bunny hop" it by jumping both wheels off the ground at the same time while moving sideways. But that's just for show offs, eh hem.
There is no question that our safety is enhanced by having these strips there. One of the most worrisome things to cyclists is an inattentive driver drifting to the right while they check their cell phone. I think its safe to say that many, perhaps the majority, of us have caught ourselves in such a position while driving. That's why PACTour encourages riders to keep a bright tail light flashing at all times - since you can be seen from farther away the chances are greater that the inattentive driver will glance up at the road when you are visible and snap out of their revere.
One of the problems with the strips is that they are effective at keeping traffic off the shoulder. What that means is the useful service that large vehicles provide of sweeping the roadway of sand, rocks, glass and debris isn't provided for us lightweights. The rumble strip budget evidently didn't include street sweepers, so the shoulder can become dicey to ride on. That's why you'll find riders like me making a trade off between risk of cars vs risk of flat tires and loss of traction in making a decision to ride on the roadway side of the strip. Besides the quality and quantity of the shoulder, factors in the risk assessment include high vs low traffic and speed of the bike. Different riders use differing weights (AKA coefficients - you remember algebra don't you?) so come to differing decisions about where to ride. I think its safe to say that everyone agrees when you are being passed by a number of vehicles and there is oncoming traffic, you move over as far to the right as you can.
The other quality of rumble strips that wasn't accounted for by the State is visibility. Naturally when the grooves are first ground out of the tarmac, its obvious that its there, as you can see from the picture above. However the cheap way to maintain roads is to "chip seal" them, which is to spray a layer of oil over the whole road, then spread small gravel on that wet oil, then optionally spray another layer of oil. Do that to a road with rumble strips and you create "invisible rumbles" like in this picture from today's ride looking toward our destination of Bozeman (at the foot of the distant mountains):
Yes, there is a rumble strip there, still quite effective at shaking the bejeebers out of you when you discover it tactilely.
OK, 'nuf of that. Today we crossed the continental divide. So long, Pacific Ocean! The sign at the divide was stolen, so we've got the crest trail sign
and Susan N perched to catch a picture of each rider as they crested the divide for the PACTour flikr album.
Here are some more photos from the Big Sky Country between Butte and Bozeman.
A quaint homestead that I wouldn't live in
Cows! Another picturesque homestead - but I could see living in this spot
Wheat!
Alfalfa!
Sporting the CalTech kit again today. We've all seen everybody's outfits a couple times by now.
The highlight of the day was stopping to visit a friend with ties to North Carolina who fortuitously lives right on the road we were riding down. She lives in a remodeled 1914 grain silo and has a fantastic collection of outdoor art.
A size large flower pot
The musical horse
Just superb ... all of it. Cycling, writing and a mind like a steel trap. Bravo!
ReplyDelete