Driving on the white line
 

I just read a comment about hypermilers "driving on the white line" to reduce rolling resistance and promote better FE. Unfortunately I couldn't find any discussion of it on the internet.

So to bring it up here... has anyone actually tried this? I wonder what the actual difference in rolling resistance is.

Driving on the white line
 

When I encounter rain, I drive on the "white line." That is, I drive on the higher, more elevated line (wheel track) where the water is not pooling. I find the center line (wheel track) to be where water usually pools.
In addition, I avoid letting the wheels drift into the very center of the road where oil drips for wet road conditions ("maximize" road adhesion).
[I am interested in what motorcyclists do about the center of the road and if oil dripping from vehicle engines onto the road is something to note.]

That is for wet conditions, and I do not intentionally drive on the white line for fuel economy reasons. However, I feel that there is an advantage to driving on the center lane, where the worn road is more polished and may contribute to less rolling friction.

I think the nickname for it is "Ridge Riding"

On brand new roads, it sometimes seems like you can feel a difference, less rolling resistance with a wheel on the line. On roads that have been in service a couple years though, the centre ridge your other wheel goes on ends up rough, uneven, and covered in oil drips, so I think you gain more RR that side than you lose on the line side, and despite being rougher, I think you're at risk for extended stopping distances in wet weather from the oil and tire crumbs. Seems the "grooves" get polished more smooth here.

In dry weather, often the grooves are smoother, so use those.

I'll sometimes ride to the right side to signal traffic that I'm going slow. They're more likely to just pass instead of tailgating me.

In the rain, I choose whatever has the least water, within the span of the lane. If that's partly on the white line, I'll ride there.

Actually, reading basjoos's post about the airspeed indicator, hanging over to the right, on a single lane each way road, would seem to have the advantage of staying more out of the "negative draft" of oncoming traffic.

Sure. I notice that effect, and move over to the right to try and avoid it, regularly.

Doh, meant right, that other left :D editing... it's from learning to drive in UK then coming over here...

It could possibly help when you've got thick lines, not thin spray-painted lines. Those are the same lines that bicyclists avoid due to low traction. They are slippery, especially when wet.

Another thing to think about though, when grooves are pronounced, like a 2 inch hump in the middle, that's like having the car lowered 2 inches when riding in them, or having it lifted 4 inches when you ride the ridge and line.

I am interested in what motorcyclists do about the center of the road and if oil dripping from vehicle engines onto the road is something to note.


I've been riding motorcycles since the late seventies and it used to be common knowledge to stay out of the center of the road because of oil drippings. When I am riding alone I always run left of center so I will be in the other drivers rear view and when riding in a group I and most other bikers alternate one left of center one right of center and so on. Even though I have been riding for 30 years I still get a little nervous when it starts to rain because of oil from cars and from the asphalt itself. Oil and water can make a very dangerous situation.

Would the climbing affect on the tire and suspension eliminate the benefit of the smoother road surface?

Is this why in LA the Freeways have those grooves cut into them?

"Black Ice"

texas tea and florida snowman are a gruesome twosome!

I suggested something similar to this years ago, on various forums, and now it's in FE books. I don't drive on the line, though, because it makes the car drift, and it's usually really rough on the other side. All the roads I've driven on are much smoother outside of the ruts, and ridges created by the ruts. When there's no oncoming traffic, I drive left of the ruts and ridges, otherwise I go to the right.

From the glossary:

WLR - White Line Rider (or Riding). A person who rides on the right side of the road, on, near or just to the right of the white line, to signal traffic they are running slower to save fuel.

I noticed white lines have low traction when wet even at red lights my tires slip for an instant as I travel over the white lines from a stop. It would make sense that they offer a less friction ride but some cars may activate the traction control causing the brakes to apply sensing one tire is slower than the other. I don't ride the white lines because of all the road trash/junk build up from the line outward to the dirt. lots of stuff that could cause a flat tire.

most of the Del. roads are very well kept. when it rains there's no deep ridges to fill up with water, I usually stay in the lane following the cars tracks in front of me. Their car splashes all the water out of the ridge so my car tracks in the almost dry ridge vs a filled up ridge.

The Motorcycle Safety Foundation states this in their rider course manual under the "Rain-slick surface" section.
"... Metal covers, bridge gratings, train tracks, painted/taped lines, leaves, and wood can be very treacherous when wet."

There is also a noticable difference in traction when dry. As a motorcyclist I try to avoid any turns or stopping when crossing a painted surface/line. Those big turn arrows near intersections cover enough ground to pose a hazard. I always try to avoid riding on a painted line or surface if possible on a bike or in car, traction and thus safety is compromised.
Just as Ford Man states I try not to ride in the middle of the road where the oil build up is, but here on the freeway it is not that bad unless it is wet. (As the song says "It never rains in sunny southern California !") Surface streets and intersections tend to have more oil build up and those tend to be a little worse.