Stephen Rees's blog

Thoughts about the relationships between transport and the urban area it serves

Posts Tagged ‘intersections

The yield to the right concept

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Not politics, but traffic regulation. And one of my hoby horses. A letter appears in the ITE Journal this month that is worth repeating here as it introduces information that I was not previously aware of. The author is Kenneth Todd, and while I do not have his permission to reproduce it I think he will be pleased that this idea is promulgated.

The yield to the right concept originated in France. Charles-Marie Gariel, a professor of physics at the School of Highways and Bridges, proposed it in 1896 as a rule when two cyclcists arrived at an intersection at the same time (source: Gariel, Charles Marie. “De la Règle à adopter en cas de Rencentre sur deux Routes qui se croisent” Revue Mensuelle du Touring-club de France July 1896 pp. 246-247) The rationale was that the cyclist on the left had no need to stop or slow down too much when yielding to the one on the right. Gariel only considered the conflict between two cyclists, not three or four.

Paris, France adopted the rule in 1910 for intersections where two roads of equal width met, and another rule gave drivers on wide roads priority over those on narrower ones. The League of Nation’s International Convention relative to Motor Traffic adopted the rule in 1926, as did the US Uniform Vehicle Code. It remains valid in all US states and by international convention in all countries where traffic drives on the right side of the road.

As William Phelps Eno, the American “father of traffic control,” and others pointed out in the 1920’s, the rule paralyzed traffic when drivers entered an intersection from all directions and obstructed others from leaving. (sources: Eno, William Phelps Simplification of Highway Traffic Saugatuck CT USA Eno Foundation 1929 p.15   McClintock, Miller Street Traffic Control New York NY USA: McGraw Hill 1925 pp 126-127  Lefferts, E B “Giving Man on Left Right of Way” National Safety News December 1922 p40) The rule is rarely in force today, but it shows that early law-makers lacked the most elementary understanding of the intersection problem. Reversing the rule so that the driver on the right gives way to the one on the left would make an intersection function like a mini-roundabout and avoid the installation of countless traffic signals.

The problem is that the ITE Journal is not read outside of the profession – you have to be a Member to get hold of it. I doubt that it is in many public libraries. So I am taking this bold step of doing more than a brief quotation in the hopes that this idea will spread.

Written by Stephen Rees

August 26, 2008 at 3:38 pm

Posted in Traffic

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