Have you ever noticed that there is no Route Q in Missouri? Nor is there a Route G or Route S. While it may seem like someone spilled their alphabet soup on a Missouri roadmap, the truth is that some letters are never used to name roads.
In fact, of the 26 letters of the alphabet, six of them are conspicuously absent from Missouri road signs. Here’s why.
G -- Can look like the number 6
I and L -- These letters look too much alike and also resemble the number 1
Q -- Too close to the letter O
S -- Looks like the number 8
X -- Film-rating designations have given this letter a bad rap
The letter R is used in special circumstances. You will not find an R used alone because they resemble the letter P. Usually it is combined with an A or a B for short state roads that go to a park or conservation area.
MoDOT occasionally receives questions concerning the choice of letters. Some people even asked if there are secret meanings behind double-lettered routes. As provoking as that may seem, the truth is somewhat less cryptic.
The lettered routes are part of the state’s supplementary system. These routes joined the Missouri system in 1952 when the state absorbed almost 12,000 miles of county-maintained roads. The letter designations came shortly after that.
The letters were assigned county-by-county. Starting with A, roads were named in coordination with adjacent counties so there would be a mix in the distribution. If the list of single letters ran dry, then double letters were used until all the county roads had a designation. The original designations have basically remained the same since then.