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White stripes and dead armadillos

Paul Alper writes:

For years I [Alper] have been obsessed by the color of the line which divides oncoming (i.e., opposing) traffic because I was firmly convinced that the color of the center line changed during my lifetime. Yet, I never could find anyone who had the same remembrance (or interest in the topic). The other day I found this this explanation that vindicates my recollection (and I was continuously out of the U.S. from 1969 to 1973):

The question of which color to use for highway center lines in the United States enjoyed considerable debate and changing standards over a period of several decades. By November 1954, 47 states had adopted white as their standard color for highway centerlines, with Oregon being the last holdout to use yellow. In 1958, the U.S. Bureau of Public Roads adopted white as the standard color for the new interstate highway system. The 1971 edition of the Manual on Uniform Traffic Control Devices, however, mandated yellow as the standard color of center lines nationwide. The changeover to the 1971 MUTCD standards took place between 1971 and 1975, with most done by the end of 1973, so for two years drivers still had to use the old and new. Yellow was adopted because it was already the standard color of warning signs, and because it was easy to teach drivers to associate yellow lines with dividing opposing traffic and white lines with dividing traffic in the same direction. . . .

Most European countries reserve white for routine lane markings of any kind. Yellow is used to mark forbidden parking, such as on bus stops.

Most countries in North and South America have yellow lines separating traffic directions. However, for example Chile has white such lines.

Armed with this knowledge, I have haphazardly been asking (annoying) American friends and relations as to what color they think the center line is now, let alone what it used to be. Young people get it right I guess because that is part of driver ed which they have recently completed; older people who drive a lot still claim the center line is white and always has been.

Wow! How could they think such a thing???

Alper continues:

If in fact so many Americans do not recall such an everyday occurrence what does this say about self-reporting and eye-witness testimony—like the famous gorillas across the screen in that classic psych study?

So, as a simple experiment is there a way of improving my haphazard sampling to give some statistical “oomph” to the contention that (older?) people are inattentive to their motoring surroundings to a remarkable degree? Redo the gorilla example by changing the color of the center line every few seconds while focusing attention on other aspects of driving? Does inattentiveness to color of the dividing line correlate with age, gender, handedness, SAT math score, religion, Vitamin D consumption, etc.?

Hmmm, could be interesting. Here’s my advice to any researchers out there who want to try this experiment. If you want to maximize your chances of getting it into Psychological Science, do several experiments, each with a nice small sample size—25 or 50 in each case should do it—and keep all your data-analysis options open.


  1. Thomas says:

    Yup…and if it weren’t for those white lines, we wouldn’t have Merle Haggard’s great song White Line Fever:

    White line fever, a sickness born
    Down deep within my soul
    White line fever, the years keep flyin’ by
    Like the highline poles

    The wrinkles in my forehead
    Show the miles I’ve put behind me
    They continue to remind how fast I’m growin’ old
    Guess I’ll die with this fever in my soul

    I wonder just what makes a man keep pushing on
    What makes me keep on hummin’ this old highway song
    I’ve been from coast to coast a hundred times before
    I ain’t found one single place where I ain’t been before

    White line fever, a sickness born
    Down deep within my soul
    White line fever, the years keep flyin’ by
    Like the highline poles

  2. I don’t think Alper should restrict his questioning to just the annoying friends friends and relations! It might be distorting the results.

    (Oh wait, that’s the kind of comment one ought to put on Language Log, not here :)

  3. Phil says:

    I am over-fond of playing the game — well, _I_ call it a game — “what did this used to be” with my friends here in Berkeley. A new store or restaurant will open, and the next time I’m walking past it with someone I’ll ask “what was here before?” Surprisingly hard, if it’s not a business you used to frequent. Evidently I can walk or bike past some anonymous-to-me nail salon or hole-in-the-wall luggage shop literally 1000 times without storing it in long-term memory, and I don’t seem to be unusual in this.

  4. G.H. says:

    Just to add to the eye-witness debate:

    * In law one learns to trust all other types of facts/proof more than eye-witness testimonies, because we permanently interpret occurances according to our personal xp

    * In emergency responder courses one learns to ask children first when getting to the site of an accident – because they are the ones most likely to just report what they saw, and not interpret the occurance (child speaks of a car and a motorbike, rest of people there – including the mother, speak of only the car… no motorcycle in sight, respoders search in the wood next to the road, find the totally hidden biker)
    Somewhere there must be data hidden about this type of thing :)



  5. Thom says:

    This isn’t really comparable to the inattention blindness with gorillas etc. The relevant literature is on memory for everyday objects such as coins, stamps and telephone dials. There is a large literature that shows that people’s memory for objects that they have had repeated interaction with over many years is prone to error and bias. Many of the studies are small n, but my recollection is that the effects are generally reproducible and large.

    The pattern is fairly similar across objects – good recognition of items but recall is good for gist but not detail, except where the detail has a functional role in their interaction with the object. This gets complicated because as skill increases often you don’t need to know certain details (e.g., in typing on a qwerty keyboard a beginner might have better memory for the location of keys than an experienced typist because the latter are largely remembering the patterns of finger movements to write a message rather than explicitly remembering the location of the keys).

    For instance, many people get the direction the Queen’s head faces (right) on coins (in the UK) wrong (typically around 70% I think) when asked to recall it or draw it, but tend to get it right on stamps (left). This could be bias or it could be because you tend to orient the stamp correctly to place in on the envelope. In the stamp-coin case I suspect it is both …

    I suspect yellow vs. white lines is like that. Experienced drivers are no longer attending to the colour cues that new drivers are and are further confused by having experiences of different colours to sample from their set of driving experiences.

  6. David P says:

    Two comments:

    1. I think cross walks have been changing, too. Not just colors, but patterns.

    2. My mother, at about age 87, driving in the city (shortly before she gave up driving): “There are a lot more lines on the street than there used to be.” (She was referring in part to the lines and arrows at intersections marking multiple left-turn lanes.)

  7. Paul Alper says:

    Just to make things a bit more intriguing about the statistics of road surface markings, consider the concept of “naked roads” inducing non-verbal communication and eye contact between drivers,

    “In the Netherlands, Germany, Sweden, and the UK, so-called “naked roads” have been trialled, whereby all visible road markings, kerbs, traffic lights, and signs are removed. When this was tested in Seend, a village in the UK county of Wiltshire, the county council reported that accidents fell by a third, with motorists’ speed falling by an average of 5%. It has been suggested that naked roads force drivers to make eye contact with other road users, and that it is this nonverbal communication that is responsible for the reduction of accidents. Other have suggested that road markings, especially with middle marker, make the road look like a main road, triggering faster and more relaxed driving, while no marking makes the road look like a lower quality road.”

  8. Phil says:

    Here is an article about getting rid of street signs and road markings in some places in Europe.

  9. ezra abrams says:

    Thank you
    If I may say so, I have often, is a sort of mini seth ian way, noted in my daily life that I thought something had changed, but I didn’t recall the past well…

  10. Chris M says:

    Attention is for doing things. Paying attention to whether line is yellow or white doesn’t help you do what you’re trying to do, which is drive. Attending to whether there’s a gorilla doesn’t help you accomplish your task which is counting the number of passes. The fact that people can neglect things that are unimportant to their task isn’t something to be ashamed of. It’s something remarkably good.

  11. Jimmy in Texas says:

    I’ve always been told yellow lines are used for separating opposing traffic lanes and white lines are for separating lanes traveling in the same direction.

    This can be very important in a heavy fog.

    I’ll be looking at my local roads in Texas to see if this holds true.

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