What are these pavement markings called? (obsolete now?)

[colinstu]

Here's a sample of them that used to be at the Mitchell Interchange in Milwaukee (now phased out with the redesign of this interchange):



I KNOW I've seen these markings used on freeways in different states... what are these exactly called? Are they still being used with new roads? They seem to be uniform in design when I've seen them used in other states. I'm assuming they tell you to slow down because you're approaching a curve... but I doubt they actually slowed anyone down (signage is WAY more effective imo).

Any other trivia or thoughts on em?

[formulanone]

I encountered those on I-75 in downtown Atlanta's HOV lanes, couldn't figure out anything specific about them except that it seemed to denote, as you said, a suggested speed reduction.

Personally, it looks like some sort of acceleration module that one might find in a video game.

[PurdueBill]

The 2009 MUTCD speed reduction markings are a lot less obtrusive into the lane.  The decreasing spacing must be done so as to create the feeling of going faster than you are, as it takes less and less time to pass consecutive markings if you maintain a constant speed through the series.

[J N Winkler]

They are not diagrammed in the current or 2003 editions of the MUTCD.  I think they were part of a localized experiment with keep-apart chevrons--if two of these are visible between you and the car in front, you are maintaining the correct two-second following distance.

[Scott5114]

From what I heard at the Chicago meet (which spent some time in Milwaukee) the idea was not to reinforce following distance, but rather that the chevrons would cause the driver to perceive the lane as being narrower, and the decreasing distance between them to perceive their speed as higher than it was. Both of these were supposed to trick the driver into slowing down.

[mgk920]

From what I heard at the Chicago meet (which spent some time in Milwaukee) the idea was not to reinforce following distance, but rather that the chevrons would cause the driver to perceive the lane as being narrower, and the decreasing distance between them to perceive their speed as higher than it was. Both of these were supposed to trick the driver into slowing down.

Yea, WisDOT was having a lot of problems with drivers taking that ramp (N/WB I-94 -> SB I-43/WB I-894 in the Mitchell Interchange) too fast so they added those chevrons in the late 1990s in an attempt to slow them down.  The new ramp in that now under-reconstruction interchange is designed to correct that problem.  BTW, that ramp will be used by the NB I-xx mainline when US 41 is 'promoted' to a full interstate in a couple of years.

Mike

[colinstu]

Thanks for all responses! Has helped me out and good to know their full name now. With that, was able to find this: http://www.fhwa.dot.gov/publications/transporter/04feb/index.cfm#safety which tells more of the same, and talks about some safety numbers etc.

EDIT: Lol yeah, TONS of pdfs are appearing now.

[hbelkins]

From what I heard at the Chicago meet (which spent some time in Milwaukee) the idea was not to reinforce following distance, but rather that the chevrons would cause the driver to perceive the lane as being narrower, and the decreasing distance between them to perceive their speed as higher than it was. Both of these were supposed to trick the driver into slowing down.

This is in use elsewhere. One example I know of in Kentucky is at the intersection of KY 9 (AA Highway) and KY 57, where these were added to turn lanes in an effort to slow traffic. A signal was later placed at that intersection, even though it did not meet warrants, because of political pressure.

[SSF]

I encountered those on I-75 in downtown Atlanta's HOV lanes, couldn't figure out anything specific about them except that it seemed to denote, as you said, a suggested speed reduction.

Personally, it looks like some sort of acceleration module that one might find in a video game.

I can verify the intention of GDOT was to slow traffic taking the exit ramp from 75 South to 85 North, that is the only location where I have seen the chevrons used in Georgia.

[kphoger]

I prefer México's use of solid horizontal lines, the distance between which decreases as you approach the curve.  I seem to recall these on northbound I-39 on the south side of Rockford as it approached a curve or tollbooth or something.  That was back in about 2007, though.

[Alps]

I prefer México's use of solid horizontal lines, the distance between which decreases as you approach the curve.  I seem to recall these on northbound I-39 on the south side of Rockford as it approached a curve or tollbooth or something.  That was back in about 2007, though.

Garden State Parkway uses such a system for all of its toll plazas.