The Manual Of Uniform Traffic Control Devices – 1938 ISHC Edition

One of the things I like about running a group like Indiana Transportation History is that I get to see a lot of things on Facebook that would normally not be accessible to me. I have a lot of people that have become “friends” on Facebook due to the group. One of those today shared something that he found in a digital library…but didn’t share it to the ITH group. He shared it to another group. But because he is on my friends list, I got to see it. It was a link, which I will share here, to the “Manual of Uniform Traffic Control Devices For Streets and Highways,” issued in 1938 by the State Highway Commission of Indiana.

Before we go much further, I guess it would be good to define the “Manual of Uniform Traffic Control Devices For Streets and Highways,” or MUTCD for short. In my post of 21 June 2019, called “Why are State Road Signs Shown as Round on Maps,” I gave a brief history of the MUTCD. It all started in 1925. Before that time, each state could make their own signs, and rules placing them. In 1925, the American Association of State Highway Officials (AASHO) started making recommendations about what signs should look like to keep them standard across the country. There was one requirement in the 1925 collection of recommendations – the shape of and legend on the signs marking the coming United States highway system.

By 1927, AASHO came out with the first manual on what signs should look like and what shape they should be on rural highways. The urban version came out in 1930. But the signs in each didn’t match entirely. The first MUTCD, combining the rural and urban versions of the highly recommended versions of how traffic should be controlled, came out in 1935.

The version that was shared on Facebook today was the one issued three years later in 1938.

Now, I have made it sound like the MUTCD is only about signs and their shapes. This is nowhere near true. The 1938 ISHC MUTCD is 60+ pages. Part I of the MUTCD is for signage. Part II is for marking…of pavement, safety zones, and pedestrian islands. The particular copy available online does not include Part III (Signals) and Part IV (Islands).

Let’s skip to part II first. Among other things mentioned in the MUTCD is that only the ISHC has the legal authority to paint any type of markings on state highways. On the other hand, the ISHC is legally not allowed to place markings on roads that are not part of the state highway system – unless permission from the appropriate local authority is given. Lines on pavements were used for the listed purposes: center lines; lane lines; pedestrian cross walks; limit lines at intersections; obstacle approach; change from two-way to one-way streets; safety zones; and parking spaces and limits.

Center lines were different than they are today. Back in 1938, the actual center line was painted: (generally) black on concrete, white on asphalt. The line in question must be four inches in width. On either side of the center line, a solid yellow line of four inches in width shall be painted. It was also mentioned in this version of the MUTCD that the place where the expansion lines in concrete pavement and the painted lines on the road should match as nearly as possible. Any confusing lines should be removed. Yellow was the standard color for most pavement markings, except for center lines and specifically mentioned instances.

As far as the signs go, Indiana only had one sign that didn’t match the National MUTCD. Yet, the pictures in the Indiana MUTCD show the particular instance as if it were the national variety. State route markers in Indiana at the time showed a rough outline of the state on a rectangular sign and a number inside the outline. The National MUTCD suggested that state road signs should be round. And the diagrams in the ISHC 1938 MUTCD show just that…round state road signs.

Most signs at the time were either white or “federal yellow” in color. This included stop signs, which were yellow in the beginning. The shapes of the signs was also important. The stop sign has eight sides because it is a more dangerous situation than the regular regulatory or informational sign. Railroad crossing signs are round – or have 360 sides – because they have always been one of the most dangerous driving situations that exist. Especially before government authorities started moving roads to eliminate or soften the crossing angle of the railroad crossing.\

Another thing included with the sign regulations is the minimum (and sometimes maximum) distance signs should be located from obstacles, intersections, and the side of the road. For instance, most stop signs, according to the diagrams in this book, are to be located no less than 50 feet from the center line of the road that crosses in front of said stop sign. That seems a bit distant…but I haven’t really looked at it before I saw this copy of the MUTCD.

Route markers came in two varieties when it came to either the US or SR markings: regular or small. The sign sizes and sign type number are shown in the following snippet. When a road changed direction, it used the G-2/G-3 signs for US routes, and the G-5/G-6 signs for state routes. There were no “advance arrow” directional signs at the time…just a shield with the letter “L” or “R” on them. Arrow signs were kept for the intersection for confirmation. That is shown in the second snippet.

The signs marking county lines appeared in 1938 much like they do today – except they were white with black letters instead of the current white on green. Another sign that was included in the 1938 edition was one that I really wish we had today: signals set for [##] M.P.H., where a speed number was on the sign to show what speed to drive to make all the lights. A snippet of that sign is included here.

There a lot more things that I would love to include in this entry. But it is best to read it for yourself, if you are interested. The shared version of the 1938 MUTCD is available at this link:

One thought on “The Manual Of Uniform Traffic Control Devices – 1938 ISHC Edition

  1. Oh man, I wish stoplights were still synchronized on main routes and that they’d publish the speed.

    In South Bend, for years the signals on Michigan St. (old US 31) were set to 35 mph north through Sample St. and then 30 mph through downtown. I can count on one hand the number of times I had to wait at a light.


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