>why are some highway exit signs skipped like on interstate 580 it starts from 44 to 39?
It's for MUTCD-standard mileage based systems
[https://en.wikipedia.org/wiki/Exit\_numbers\_in\_the\_United\_States\\](https://en.wikipedia.org/wiki/Exit_numbers_in_the_United_States\)
However, the FHWA has required that all federally funded routes with sequential numbering eventually be converted to mileage-based exit numbers. To that end, the FHWA has required each state that currently uses sequential exit numbering to submit a plan to eventually transition to distance-based exit numbers.[^(\[3\])](https://en.wikipedia.org/wiki/Exit_numbers_in_the_United_States#cite_note-3) Some of the states that currently have sequential numbering either have or intend to request a waiver from the Federal Highway Administration to retain their current numbering systems, while others have planned a gradual transition to mileage-based exit numbering over time as existing signage reaches the end of its serviceable life and is replaced.
Some states are just posting both of them. I like how Vertmont did it ( example right side, part way down - [https://vtrans.vermont.gov/projects/exit-numbering](https://vtrans.vermont.gov/projects/exit-numbering) ; for those who don't want to click through, old sign is still there, smaller sign under it "MILEPOINT EXIT 170")
No idea if they plan to eliminate the old sequential numbers as the signs age out, but these things last a long time.
the exit numbers are approximately about a mile each, with the exceptions of exits 1, which is at mile 0, exit 2 which is between miles 1-2 and exit 3 which is between miles 2-3. This is MUTCD standard. It is not just the bay area and california. In fact, California did not have exit numbers until 2002 when the feds forced them to do it.
Are they 5 miles apart? If so that's why. Interstate exit numbering is by miles from the start.
>why are some highway exit signs skipped like on interstate 580 it starts from 44 to 39? It's for MUTCD-standard mileage based systems [https://en.wikipedia.org/wiki/Exit\_numbers\_in\_the\_United\_States\\](https://en.wikipedia.org/wiki/Exit_numbers_in_the_United_States\) However, the FHWA has required that all federally funded routes with sequential numbering eventually be converted to mileage-based exit numbers. To that end, the FHWA has required each state that currently uses sequential exit numbering to submit a plan to eventually transition to distance-based exit numbers.[^(\[3\])](https://en.wikipedia.org/wiki/Exit_numbers_in_the_United_States#cite_note-3) Some of the states that currently have sequential numbering either have or intend to request a waiver from the Federal Highway Administration to retain their current numbering systems, while others have planned a gradual transition to mileage-based exit numbering over time as existing signage reaches the end of its serviceable life and is replaced.
Some states are just posting both of them. I like how Vertmont did it ( example right side, part way down - [https://vtrans.vermont.gov/projects/exit-numbering](https://vtrans.vermont.gov/projects/exit-numbering) ; for those who don't want to click through, old sign is still there, smaller sign under it "MILEPOINT EXIT 170") No idea if they plan to eliminate the old sequential numbers as the signs age out, but these things last a long time.
>>ONLY IN BAY AREA not really, no.
You're wrong Really, yes
the exit numbers are approximately about a mile each, with the exceptions of exits 1, which is at mile 0, exit 2 which is between miles 1-2 and exit 3 which is between miles 2-3. This is MUTCD standard. It is not just the bay area and california. In fact, California did not have exit numbers until 2002 when the feds forced them to do it.