Another thread had me thinking about this. US 59 from Cleveland to Livingston (and Lufkin has it too) has not had the I-69 fairy tap it on the forehead yet, so there are some exits in Cleveland, Shepherd and Livingston with exit numbers. I was driving this stretch this weekend and noticed something weird. The numbering ascends southbound which tells me it's Texas reference marker based, but the odd thing is, all the exits have letter suffixes. In Shepherd, the first exit heading northbound is 453B, then the second is 451B. Why are they letter suffixed? Even more perplexing is they have different letter suffixes in the southbound direction. Southbound the exits are 451C and 453A. Why does Texas have to do things so weird? Makes me think of US-75 coming out of Dallas, for some reason has exit numbers, and they are sequential, and so does US 54 in El Paso and they start at 22 for some reason. Why does this crap happen? At least I-17 has an interesting story as to why it starts at mile 194. Why does Texas have to use the stupid reference marker system and why don't they just go to mile markers like smart people?