Re: German ߫

From: Neil Harris <>
Date: Sun, 17 Feb 2013 18:52:01 +0000

On 17/02/13 10:48, Philippe Verdy wrote:
> I was not citing empirical results but things that are regulated by legislation.
> And your existing empirical results are just nfomal tests ignoring
> important parts of the population of drivers, notably:
> - those driving by night : the effet of some visual defects like
> asygmatism, which is only partially corrected and which can only be
> compensated by sufficient contrast (lowercase letters do not contrast
> enough, because their strokes are too near of each other)
> - the effect of presbytia on vision of aging population : here again
> the size of letters does matter (look at those phones sold to ages
> people: most of them are completely unable to use modern smartphones
> for example, they are unreadable even with the best visual
> correction), even if they wear "progressive glasses", they have a
> reduced angle of good focusing, and if letters are too small, they
> need to stop looking at the road to fix the displays on roads for
> longer time. Every people above the age of 40 starts suffering this
> visual defficiency where adaptation to vision depth is more difficult
> and longer. larger letters that can be read easily even before there's
> a full focus helps reducing the adaptation time.
> - also by night, the effect of tireness also slows down the visual
> adaptation and reduuces the angle of good focusing.
> In all these cases, you need less density of strokes, and capital
> letters are better constrasting.
> Of course there are other factors like the effective constrast of
> colors used on those displays, the negative impact of too narrow
> fonts, insufficient intercharacter advance gaps, and insufficient
> boldness.
> Note that a perfect 10/10 vision (or better) is not mandatory to
> drive, there are legal minimums where people with only 8/10 can
> legally drive (and other visual defects are NOT tested at all, notably
> the various forms of color blindness (mot cases being full or partial
> deuteranopia, affecting about 1 on 6-8 male human in Europe, depending
> on test methods : this is definitely not a small population).

Here are some excellent articles about the evidence-based approach that
led to the development of current road signage in the United States.

and this, on research on the legibility of mixed/lower case vs. ALL CAPS:

Regarding Clearview and older drivers, this:

is particularly interesting: the take-home quote is this:

> The greatest improvement in legibility distance afforded by Clearview
> was realized by older drivers when viewed under headlamp illumination
> during nighttime conditions (an increase in legibility distance of
> between 6.0 percent and 6.8 percent)

-- Neil
Received on Sun Feb 17 2013 - 12:55:25 CST

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