Highway spin off- Exit numbers

[sam_gordon]

I had assumed all the interstates had changed exit numbers to match miles markers decades ago. But I'm in Vermont and for I89, they still have sequential exit numbers (14, 15, 16) instead of basing it on the closest mile maker (88, 90, 92). There are added signs at the bottom showing the mile marker. Sample pic from Google street view...

So, my question, in your AREA, are the exit numbers sequential or based on mile marker?

 

[mickeyboat]

I live in Vermont - you already know my answer.

 

[wvjules]

It's mixed here, depending on the road.

I prefer mile marker based exits. So much easier to determine how "far" until the next exit.

 

[mumto3girls]

The one closest to me changed to mile marker years ago—assuming others in the area did the same, but haven’t really paid attention.

 

[jimmalru80]

NJ - Mixed

 

[sam_gordon]

I prefer mile marker based exits. So much easier to determine how "far" until the next exit.

Totally agree. AND, what happens if an exit gets added in the future? Let's say there's an exit added between 14 and 15. How does that get numbered?

 

[leebee]

Totally agree. AND, what happens if an exit gets added in the future? Let's say there's an exit added between 14 and 15. How does that get numbered?

In Maine, the new exit would be 14A. Maine also uses the A/B designation if there are two exits for one roadway. For example, if you are on a N/S highway and are exiting to an E/W highway, there might be two exits, one for the east bound connection and one for the west bound connection, designated as 182A and 182B.

OP, Welcome to New England...
Maine has gone over to mile markers, but many exits also say "Old Exit XYZ"
I know people prefer mile markers usually, but how would you do this in a major city, where the highway exits are often one right after the other, maybe 1/10th of a mile apart or something like that?

 

[geargrinder]

State highway engineer here.

Exits numbers on interstates are based on interstate mileposts and begin and end on the state lines.

Some confusion can come when a state installs Interstate mileposts (these would match exits) as well as county based route mileposts ( these are usually white with a county designation).

Odd numbered interstates travel North/South. Even numbered interstates travel East/West.

Route numbering and mileposts begin and have lowest numbers in the West and South. End had have highest numbers in the East and North.

 

[nancipants]

I know people prefer mile markers usually, but how would you do this in a major city, where the highway exits are often one right after the other, maybe 1/10th of a mile apart or something like that?

Same as above - use A, B, C.

All the city exits (and major interchanges) are like this in FL.


When I was younger, everything was sequential, but they switched around the time I started driving.

 

[kdonnel]

They are all by mile on the sign but some of them still live in my head by sequential number.

 

[Sacahara]

Kinda mixed since we get all mathy around here and start adding letters into the equation lol.

 

[sam_gordon]

I know people prefer mile markers usually, but how would you do this in a major city, where the highway exits are often one right after the other, maybe 1/10th of a mile apart or something like that?

As mentioned, A, B, C, D, etc. Exit 1 on I-75 in Cincinnati goes up to G...

Mileposts are usually based on county beginning and end.

On county or state highways, yes. But on interstates, they start/end on state borders.

 

[mjkacmom]

NJ - Mixed

One of the reasons I hate the turnpike.

 

[geargrinder]

As mentioned, A, B, C, D, etc. Exit 1 on I-75 in Cincinnati goes up to G... View attachment 782616


On county or state highways, yes. But on interstates, they start/end on state borders.

Depends on the type of mileposts. There are Interstate mileposts and County mileposts.

Interstate mileposts begin and end at state lines. County mileposts begin and end at each county.

Interstate mileposts are usually green. County mileposts are usually white.

I edited my original post for clarity between the two types of mileposts.

 

[mjkacmom]

In Maine, the new exit would be 14A. Maine also uses the A/B designation if there are two exits for one roadway. For example, if you are on a N/S highway and are exiting to an E/W highway, there might be two exits, one for the east bound connection and one for the west bound connection, designated as 182A and 182B.

OP, Welcome to New England...
Maine has gone over to mile markers, but many exits also say "Old Exit XYZ"
I know people prefer mile markers usually, but how would you do this in a major city, where the highway exits are often one right after the other, maybe 1/10th of a mile apart or something like that?

My exit from the NJ turnpike is 15 W, route 3 west. 15 E is east heading towards the city. This was never explained to me when I was younger, can’t count how many times I ended up heading east.

 

[AppleDumpling]

In my local region, NYC metro/“downstate”, they are mostly sequential. Some roads upstate are mileage-based and some are being converted from sequential to mileage. So mixed.

I honestly don’t pay much attention to it. If I’m driving anywhere outside of my home area, I generally use a GPS map app and follow the navigation system.

 

[geargrinder]

Here's a link to some information from the Federal Highway Adminstration about highway and exit numbering.

https://www.fhwa.dot.gov/programadm...SHTO developed the,numbered run east and west.

 

[RedAngie]

Totally agree. AND, what happens if an exit gets added in the future? Let's say there's an exit added between 14 and 15. How does that get numbered?

The New Jersey Turnpike added many in between exits since it was built.

There is 7A, 8A, 13A. An extension from Exit 14 has 14 A, B, and C. North of there the turnpike splits into eastern and western roads. There are exits 15 E and W, etc. before the two separate roads come together again at Exit 18, the end.

 

[disneychrista]

I've only seen sequential

 

[RedAngie]

In Delaware I-95 exits are numbered sequentially, although for whatever reason a few numbers are skipped.

Delaware Route 1 has exit numbers based on kilometers. The road was planned in the 1970s but wasn’t even started until the early 90s. The US was supposed to be fully metric by 1985 or so. They decided to keep the metric exit numbers but there are markers along the side of the road in miles.

I’m at Exit 160, which is about 100 miles from the southern state line.