Road Surface Roughness
 

This may seem trivial but the other day I was thinking how much does the road surface play into efficiency. I guess this falls into the same area as water spray in the rain. Is this another reason to "ride the rails" on the road. I know I have started.

The noise level is certainly higher, thus there is more energy spent creating that sound as the tires flex over the surface. Not to mention pot holes and patches.

I do not have a scan gauge to test this out, is there anyone out there willing to try? :)

Every little bit counts. :thumbup:

Many thanks!!!

Unofficial Data
 

On an unofficial basis, I've noticed the ability to coast further on asphalt -- so less friction = better FE, for example

-New asphalt is the best (but doesn't last as long as concrete)
-Concrete isn't as good -- seems to take more energy to push the tires over the surface's imperfections (but last longer, is more expensive to pave)
-Worn concrete gets smooth, but the expansion gaps between sections take a beating over time and create friction-robbing bumps, that are generally sealed with asphalt.
-"Chip and Seal" has to be the worst as it's nearly like gravel when new, but smooths-out as it wears down to the tar
-Gravel is the worst with FE, but the most fun :D
-No offense up there, but Iowa has the loudest, roughest Interstates. I don't know what they use but I believe "Car and Driver" mentioned the same once (and I agree from experience).

Fun Fact: Sections of Washington State's Interstate Highway System still has some of the original pavement from almost 50 years ago (due to the granite-like quality of the stone used from local quarries).

Here's a site that I've used for cycling. if you look to the tool bar to the right it gives the Coefficient of Rolling Resistance for different road types. So yes there is a difference in types.

On the bike which would also translate to the car. On a wet road the painted lines offer less resistance then the unpainted parts. Roads have a crest for drainage so the top is the place to be when wet. Is it enough to make a difference? "Shrug"

Hey, do you have SVOboys permission to use that word? I think owns the rights to that ;)

I do a lot of roller blading in the summer, big difference in rolling resistance between different surfaces. Smoothed out older concrete is the best followed closely by new blacktop.

I was not aware that he owned it but after looking at his avatar I see the word *shrug* not "shrug". I've had a battery of $500/hour solicitors look at it and they assure me that there is no infringement but for the harmony of the boards and my respect for SVOboy I will refrain from it's further use.:p

Saskatchewan has a vast abundance of gravel roads and I will tell you that the MPG impact is destructive. I usually lower my speed by a good 5-10mph on gravel and STILL get less mpg than if I was going faster on paved roads. I haven't really tested any true Scanguage readings but I remember one trip I was getting ~49mpg @ 50mph on paved highway, and then ~43mpg on a gravel road in the same direction when travelling at around 45mph.

Gravel roads = MPG death.

Tell me about it, I was "enjoying" some of these 50 year old concrete sections on I-5 last weekend in my smart, when my wife and I went to Seattle for the day and a dinner date. There are some bits of I-90 to the east of the Columbia River that are really poor too.

Smooth concrete or asphalt,,, I cant tell the diff.

Course asphalt is a killer. And whats up with all this fine grooving they are doing on concrete hwy's here in Oklahoma... The tiny grooves suck big time.

Yea, I get to drive on that nastiness all the time and is the reason I thought I started this thread, the vibrations and noise rattled the question out of my head!! :rolleyes:

The problem is between the granite the cement is missing, mostly due to the studded snow tires that are allowed in the winter. In addition to the rough surface grooves are worn in the surface where the water pools when it rains. It rains a little bit in Seattle so you get troughs of water. Nice.

Plus, as you mention, the expansion strips are raised shake the #$% out of the car at speed. That really hurts.

Thanks for the comments.....

A few years ago I took a trip in my Insight to TX. On the way back we decided to take backroads America - TX to FL. When I went from the nice two lane roads of TX to garbage 2 lane roads of LA my FCD (fuel consumption display for newbies) went from a constant 100 MPG to around 60. It stayed there until we made it to better road.

While conversing on a hybrid website, I argued that in my plea as to why I got such cruddy mileage (avg went down to around 58) on my trip and was told I should be able to get great mileage no matter what. IMO shallow hills kill mileage too, I had those and the the bad road on that trip even though I was travelling in the car's "sweet speed" area - 50mph. Still that 50mph only yeilded 58mpg.

Short answer - YES - IMO bad/rough roads murder mileage.

Many of the roads hear are 50 year old concrete. Very rough with many cracks (some asphalt filled some not filled).

They're doing that up here in KC too -- the grooves are supposed to prevent hydroplaning by channeling the water. Confused me because in dry weather it tosses the car left and right, which isn't the best of "stability", but the DOT found that on corners or low-spots, it prevents pooling.

What confuses me about Tulsa is the street numbering "system". What the heck is East 81st Street South? If I try to get around there without the GPS, I'm sunk (even though I'm there every 4-weeks -- you think I'd learn :rolleyes: ).

Shoot, I've only been there once, and I know that East 81st Street South is on the southeast side of downtown, about 8 miles south of downtown. About a mile south of 71st, which is also called Memorial. Keep trying rh77! You'll get it!

Corner of S 97th E and E 81st S
 

Ah, careful Bill -- 71st Avenue is "Memorial". But there's also a 71st Street. I would usually get my morning coffee at essentially the corner of 71st and 71st.

So, the place was on South 100th East Avenue. But there's also an East 100th Street South. Without a map and trying to "wing-it" led me to a grassy field in the middle of nowhere. It turns out the place was near the corner of 97th (Mingo) and 81st. :rolleyes:

There are much worse places to navigate, but I'll admit to getting lost pretty easily. :o

Michigan's got some areas with grooved pavement. Hate it! Makes me want to drive faster just to get back to ungrooved pavement. Makes my Saturn feel like it's on ice even when in the dry. I've had an alignment not long ago. On straight, ungrooved pavement I can let go of the wheel and the car drives straight. Tires follow the not-perfectly-straight grooves, shimmying side to side. WTH! Takes alot of left/right compensating with the steering wheel to keep straight. Even worse with the strong crosswinds lately. Thanks, MDOT! NOT!!

Must be a traction enhancement pipe dream of the road commissions. Not effective, I don't think. Maybe to get drivers to slow down? Could be. Rain water in the grooves only increase the changes of hydroplaning. Melted snow that's turned to ice builds up in the grooves. A plow truck misses the ice in the grooves. Only rarely do the plows get right down to the pavement. They leave a 1/8 inch or more for the salt/sand trucks to go over. Until then, it's an ice rink.

See? Perfectly simple! :-) I got a headache trying to makes sense of it. And I didn't like how they changed some to names vs numbers, like Memorial, Mingo, etc. Have you ever been to Salt Lake City? There, you can end up trying to find 2631 East 2400 South. Makes my head spin, even though I know it's supposed to be perfectly logical.

Tulsa isn't hard to get around in... Its a grid. North/South streets are by name like Memorial, Harvard, Mingo, Garrnett and such. With a sub number and alpha Avenue. Street numbers run East/West. IE 71st, 11th, 101st. If your north of Admrial it would be 71st north.

Anyway,,, rh77. Lets do lunch sometime when your in town.

As for the roads. Ive dug around a bit on the concrete grooving issue. Ive got so frustrated with it. Its not even funny. Ive email the Okie folks for explanation and cant get one. Ive heard its for water control, traction. And the worst of all smoothing out bad work done by the construction crews. O and reliving surface tension so the road will last longer.

Either way the grooves ruin mpg. The tossing around of the car or motorcycle doesn't bother me. On a motorcycle you learn real quick to just let it jump around. Fighting it may very well result in getting yourself thrown down on the ground. As for cars. Soon as I hit the grooves it requires more throttle input to keep up speed. Never mind coasting... The bastards... Also since they have started doing this retarded grooving on the roads the wife and I drive daily. Our tire wear has went way up. And what gets me is where they groove them at. Never in a known hydroplaning area. Will be leading up to and on the down side of a over pass. Never the over pass its self that will freeze first.

It makes no sense to me at all. Best I can figure. Here in Oklahoma we have some over educated idiot in OKC ripping the tax payers off with fuzzy numbers. I would like to meet the person. Man or woman and give them a swift kick in the groin, and hope they don't breed.

psy

I wonder if those grooves bring the static friction coefficient above 1.0. I see how they are necessary, but that would totally suck :P

I'm still waiting for photo voltaic road panels and driveways :P At full capacity only 5-10% of the road surface is actually covered by car :P

Check out
https://www.everytime.cummins.com/eve...Whitepaper.pdf
lots of good stuff. It was directed at truckers, but most of it carries over to us as well.

smooth concrete -12%
new concrete 0 - baseline
Asphalt finish +1%
Asphalt med +4%
Asphalt coarse +8%
chip seal +33%

oh I dislike chip seal. Only our big interstates are concrete up here in WI, I can see the inporvement in mileage on them.

We have very few roads made with concrete up here (just a few select high-traffic intersections). You guys in the 'States have entire freeway systems made with concrete? I wonder why they don't do that up here (my guess is that the freezing and thawing would be murder on the roads)?

The road surface makes a noticeable difference. Some of the roads where I live are not very good, because trucks drive on the repeatedly. The recently resurfaced areas are so smooth, and I can coast for ages, and speed up easily when coasting down gentle slopes, and the 'bad' areas, which have no potholes, but are very rough, and make the whole car vibrate, result in a noticable 'braking' effect, so in these areas I try to stay on the least damaged areas, and doing that today managed to coast a lot further.

The Road
 

First, Brock -- excellent find on the Cummins article! This should be required reading for anyone looking to get better FE. Although geared toward big-rigs and diesel engines, I would say that a majority of the content still applies to any size vehicle or engine design.

Peakster -- I think you're right about the freezing. In the 'States, there are 1000s of miles of Interstate concrete. It lasts longer from a wear perspective, but is much more expensive than asphalt. The joints do take a beating, especially in freezing temps and require more maintenance. Concrete projects take longer to complete as well. Gov't agencies have to decide, "Quick and Cheap" asphalt (which is also quieter), or pay more up-front (time and cost) for a longer lasting stretch of road. Also sourcing the materials is a factor.

Great stuff Brock, thanks!!

The cummins info is wonderful. Just look at all the drafting that can be done around those rigs.

In traffic I love the side draft as long as the wind is right. Also love to surf them out front.

Road surfaces have always been of interest to me.

I'm looking forward to a little over night trip the wife and I are taking to Arkansas this week. We are both on vacation this week. She has never been to Eureka Springs. So we are going to steal away for a overnight romp in the Ozarks. Im looking forward to some awesome driving. I haven't been there in many years myself. So it will be interesting to see the road surfaces and have some hypermiling fun.

We will have to drive more miles than I care to think about on the grooved concrete roads. :(

psy

Eureka Springs
 

If you like cornering (and great scenery), Highway 62 into Eureka Springs from Rogers is one of the most curvy and challenging roads around the area. Unless you get stuck behind a slow RV or something, you can get exhausted from the switchbacks, but it's a blast! The elevation changes are pretty extreme too so coasting is a possibility, but burning up a lot of fuel is too :rolleyes:

Have a good trip!

We will be going in on 62. :) :) :). I will lay waste to motor homes and semis. And digging hard in fas off some of the ridges in the the nice off and on camber turns that await us at the bottom. :) We leave out the south way and over to springdale and the Fayitville area.... Stop by and pay my respects to hogdom. Then shoot south to Alma on old 71 or 540.

The wife has been in the area on a bike with me. Which becomes a blurrrrrr to her. ( Better than sex IMO ) and we took the Accord over there for a short romp right after we purchased it. Plulling out of Alma heading north on 540 it struck me like a bat on the head,,, Damn Im doing 100 mph or better. about 115 when I looked at the speedo a second time. Dont ever let anybody tell you a I4 Accord or TSX is a slug... Ive layed to waiste more so called road machines on old 71 than a preacher has followers on bikes and in cars. Hell we might even run over twords Harrison then drop back south to I-40. Its all good as long as I dont go near Little Rock and the god awful delta. :)

Im sooooo looking forward to this drive....

psy

Not to steal the thread,,,, sorry

One more Jack
 

Sorry to further hijack a perfectly good thread, but you're speakin' my language in an area that I love to drive.

The I4 Accord rental proved your point to a 'T' in the hills around Little Rock. What a rush and a surprise on how composed it is.

My wife and I were married at a woodsy chapel in Bella Vista (about 5 miles North of Bentonville). This place is breathtaking -- mostly glass and arched steel to blend-in with the treed surroundings. So, driving between E.P. and Rogers with the In-Laws and the wife in the car, I had to maneuver the rental Taurus with the least yaw and easy brakes. By the time it was over, I was sweatin'! All passengers were pleased, whew! (I had visions of my car at the time -- the Evo -- blasting around the course).

If you like German food -- there a great German/Austrian place just as you get into Eureka -- can't miss it -- looks like a chalet.

OK -- I'm done -- back to topic.

Highway 62 is recently paved ashphalt cut through the Ozark Mountains, so it should provide some reduced rolling resistance :p

Have fun!

new awareness
 

With my new awareness of surface roughness I have altered my lane choices. I did notice that on an uphill coast portion of my trip home with new pavement that I lose very little momentum at all, while on a down hill portion with old rough pavement that car slows noticeably. Hmmm, I am sure the lugged snow tires magnify the effect.....

David:
I remember the grooves, I previously lived in Michigan. Each time I have been back for a visit there seems to be less and less of the nasty stuff left.

Which highway are you referring too?

When is winters back going to be broken in WA. Snow Tires?:eek:

winter
 

Beats me, there was ice on the car this morning!!!! Friday was nice, almost 70 degrees. I had to EOC in order to keep the car from overheating!!! Great insentive!!

I have been working on new tires for the summer. I have a feeling that my autocross tires are not going to help my mileage, they weight a ton and are intentionally wide.

I found another government report (https://onlinepubs.trb.org/onlinepubs/sr/sr286.pdf) that indicates General Ameri G4S was a decent roller and in my preferred FE size 175/70, plus they are $35 a tire. Dang.

Tax dollars at work
 

Awesome find! Finally a new report on the subject.

New Report
 

I was search around the forums to see if it had been referred to anyplace.

Is there a better location to post this? I will start a new thread...

New Thread
 

After I looked at it, there seemed to be the same Green-Seal Report data listing the newest, specific tires (which was 2003). It's a good report, worthy of its own thread, though. I say go for it -- very good reading on the the overall efficiency of tires and the vehicle itself.

That is what I thought, I will start one up!!!