Highway exit numbering when new exits are added?

Question

When highways run thru rural areas that are developing or have developed, exits are sometimes added to serve these areas. I would like to know how these exits are numbered. Exits are usually numbered sequentilly so if an exit is added, does that than affect all the subsequent exits as in they are all bumped up or down one number?

Thank you

Answer 1

All exit numbers I have seen are according to the "mile marker." For example, if there were an exit one mile from the state line, that would be exit 1. If it were 25 miles from the state line, it would be exit 25. Therefore, many numbers are "skipped" where there is no exit in those miles. When an exit is added, there is no problem assigning it the proper sequential number. In metropolitan areas, where there are several exits within a single mile, you will find that those exits are marked with letters, such as Exit 20A, 20B, 20C, etc.

Answer 2

Exits are numbered counting up from the south and from the west. The exit is numbered according to the mile in which the exit ramp starts. I've seen ramps exit the highway then the mile marker on the highway occurs before the crossing road. Does that make sense?

Answer 3

All the answers given are correct. Florida formerly used Exit numbers that did not correspond to mile markers. They have in recent years renumbered the Exit numbers so they now match the milemarkers. Quite confusing if you were directed to Exit 21 and all of a sudden you find it is Exit 154. Once relearned, is much better

Answer 4

It is to allow 'foreigners' (visitors from the other 49 states) to be able to drive more easily in California. The State was getting too many complaints about all of the Spanish-named roads (eg San Francisco, San Mateo, San Jose, San Juan Bautista, Tujunga, Cajon Pass, Ft Tejon, San Diego, San Clamente, etc) and road abbreviations (eg Cyn for canyon, Pkwy for parkway, etc) that visitors were getting confused where to exit from the freeway. Visitors were accustomed to numbered exits in their home states, but just couldn't cope with the randomness in California. So, the powers-that-be in Sacramento (another Spanish name) finally relented and somebody wrote a law to change the signs. Soon thereafter, Caltrans starting adding exit numbers on new signs. I recall seeing some of the first numbered-exit signs being installed on I-80 between Colfax and Truckee (name of a Native American Indian chief.) Now, number signs are going up everywhere, and I'm sure that adhesive signs will be retrofitted on existing signs if possible. Take it with a grain of salt during the transition. In a few years, it will seem 'natural' and you'll wonder why it wasn't done sooner. Just pray that they don't decide to change all the distances to the metric system - they would have to replace tens of thousands of signs across the State.

Answer 5

They're not numbered sequentially, at least around here. Interstate exits are numered according to the mile markers. If there happens to be more than one exit per mile during any point, the exits are assigned a letter after them, like exit 182A and 182B.

Answer 6

You get A and B exits

Answer 7

most of the time they are numbered by miles, since the exits are not on the same mile marker, they will be different

Answer 8

it varies by state. most states number their exits by milepost rather than a specific #.

Answer 9

Bho.....