Mile-based exit numbers are better because numbering sequentially causes problems whenever they wanted to build a new exit between existing ones 'cause you can’t just go around renumbering them all the time. Even resorting to adding letters (e.g. having exit 42A, 42B, etc.) only gets you so far (although they still do that with mile-based numbering, for multiple exits within the same mile).
The Interstates in my state used mile-based exit numbers but state routes do not, and I remember when GA 400 got renumbered because they added an extension with four extra exits on to the beginning of it.
They should switch to kilometer-based exit numbers, so they could stack more exit per mile without needing to add letters!
Thank you for coming to my ted talk.
Eh, in practice it wouldn’t net you much. In cases where you have, say, 3 exits within a mile of each other, they’ll fudge it a bit and number them, for example, 15, 16 and 17 even if they’re really close to mile 16. At typical interstate speed limits, you’d have to encounter an exit every 30 seconds for 4 straight minutes for it to really be a problem.
Lettering exists like 42A and 42B are usually used for junctions between divided highways, that is, exits that take you different directions on the same route. Say you’re going northbound on I-55, and you’re approaching the junction with I-50. Exit 42A will be encountered first, before the overpass, and will take you on a ~90 degree curved path to merge onto I-50 East. Exit 42B will be next, after the overpass, and will take you on a ~270 degree spiral to merge onto I-50 West.
Compare this to exits that lead into city streets, in which case you’re exiting the interstate system entirely, these will usually just be numbered, and on interstates they’re usually not that many that close together; you don’t have an exit from an interstate every block through a city.
Note: There is no Interstate 50; if there was one it would cross I-55 in Southeastern Missouri. I-50 and I-60 were skipped because they’d be confusingly close to the pre-existing US-50 and US-60 highways.
One thing I love about lemmy (and I promise there’s no sarcasm here) is that I can post about numbers being used and someone will respond “here’s why numbers are better!” I genuinely enjoyed and appreciate your post.
Mile-based exit numbers are better because numbering sequentially causes problems whenever they wanted to build a new exit between existing ones 'cause you can’t just go around renumbering them all the time. Even resorting to adding letters (e.g. having exit 42A, 42B, etc.) only gets you so far (although they still do that with mile-based numbering, for multiple exits within the same mile).
The Interstates in my state used mile-based exit numbers but state routes do not, and I remember when GA 400 got renumbered because they added an extension with four extra exits on to the beginning of it.
They should switch to kilometer-based exit numbers, so they could stack more exit per mile without needing to add letters!
Thank you for coming to my ted talk.
Eh, in practice it wouldn’t net you much. In cases where you have, say, 3 exits within a mile of each other, they’ll fudge it a bit and number them, for example, 15, 16 and 17 even if they’re really close to mile 16. At typical interstate speed limits, you’d have to encounter an exit every 30 seconds for 4 straight minutes for it to really be a problem.
Lettering exists like 42A and 42B are usually used for junctions between divided highways, that is, exits that take you different directions on the same route. Say you’re going northbound on I-55, and you’re approaching the junction with I-50. Exit 42A will be encountered first, before the overpass, and will take you on a ~90 degree curved path to merge onto I-50 East. Exit 42B will be next, after the overpass, and will take you on a ~270 degree spiral to merge onto I-50 West.
Compare this to exits that lead into city streets, in which case you’re exiting the interstate system entirely, these will usually just be numbered, and on interstates they’re usually not that many that close together; you don’t have an exit from an interstate every block through a city.
Note: There is no Interstate 50; if there was one it would cross I-55 in Southeastern Missouri. I-50 and I-60 were skipped because they’d be confusingly close to the pre-existing US-50 and US-60 highways.
One thing I love about lemmy (and I promise there’s no sarcasm here) is that I can post about numbers being used and someone will respond “here’s why numbers are better!” I genuinely enjoyed and appreciate your post.