Roads with exits that are about 1 mile apart

[hotdogPi]

For sequential numbering, this means that converting to mile-based numbering would have little or no effect.
For mile-based numbering, this means that the numbers are sequential or almost sequential.

Examples:
MA 213 (sequential)
MD 100 (mile-based)
I-264 VA (sequential)

[NE2]

The two renumberings of I-595 FL's exits are left as an exercise to the reader.

[SectorZ]

For sequential numbering, this means that converting to mile-based numbering would have little or no effect.
For mile-based numbering, this means that the numbers are sequential or almost sequential.

Examples:
MA 213 (sequential)
MD 100 (mile-based)
I-264 VA (sequential)

Don't forget I-93 in MA too, I believe distance in miles and final exit number are within 1-2 of each other, and more than a few exit numbers would remain unchanged if/when MA finally changes to mileage based exit numbers.

[hotdogPi]

For sequential numbering, this means that converting to mile-based numbering would have little or no effect.
For mile-based numbering, this means that the numbers are sequential or almost sequential.

Examples:
MA 213 (sequential)
MD 100 (mile-based)
I-264 VA (sequential)

Don't forget I-93 in MA too, I believe distance in miles and final exit number are within 1-2 of each other, and more than a few exit numbers would remain unchanged if/when MA finally changes to mileage based exit numbers.

The southern section (exits 1-13) would qualify, and the northern end is off by 2. However, the middle of the route differs by about 10.

[vdeane]

I-890.  Ironically, it is one of the four roads in NY that have mile-based exit numbers; the only evidence is exit 4C, which might end up renumbered when the interchange is reconfigured in the next couple years.

[pumpkineater2]

Phoenix area freeways are like this in most places due to the fact that the near perfect street grid is spaced at 1 mile intervals.

[dgolub]

The Connecticut Turnpike (I-95), especially south of New Haven.

Also, the Belt Parkway and Cross Island Parkway combination.  The exits there are on a milepost system, but most people probably don't realize it.

[Duke87]

Also, the Belt Parkway and Cross Island Parkway combination.  The exits there are on a milepost system, but most people probably don't realize it.

Are they, though? Directional suffixes are used in several places, and a lot of the numbers are off by 1 or 2 from what they should be if they really were determined by mile marker. Also, exits 10 and 12 being missing from the seqeunce could be just as easily explained by those being the implied exit numbers for Plumb Beach and Jamaica Bay Riding Academy. Dunno why there's no 16, though.

[vdeane]

Exits 13-15 in particular are each one mile farther than they should be under a mile-based scheme.  Since there's no 12, if they used mile-based, they could easily have the correct numbers.

The Connecticut Turnpike (I-95), especially south of New Haven.

That assumes the exits are evenly distributed.  They are not.  There are a few longer gaps, but they're offset by the large number of interchanges in Bridgeport.

[roadfro]

A section of I-80 in Reno—Sparks, NV, meets the definition. While the exits are seemingly mileage-based, they are actually sequential from roughly US 395/I-580 (exit 15) to Vista Blvd (exit 21). While I-80 uses mileage-based exit numbering (as does all of Nevada), many of the interchanges along this stretch are actually closer than one mile apart. The exit numbering in this stretch was likely altered to avoid having suffixed exit numbers for separate unrelated interchanges (notably, the 395/580 system interchange would be exit 14B). The numbering alteration also becomes apparent when one realizes there is about 3 miles between exit 21 and exit 22.

[SSOWorld]

Parts of the east beltline in Madison have 4 exits within a mile.  So much so that a BGS has a 1/8 mile ahead on it.

The rapid-fire ramps of the Kennedy just west of the Chicago Loop near the Circle.

[bzakharin]

I-76 through Philadelphia has exits 337 through 351 more frequently than every mile, though no-one would confuse them for sequential (especially since they used to be not that long ago).

[OCGuy81]

Looking at a map, it seems I-10 heading west out of Houston is very straight and looks to have an exit about every mile.

I haven't driven that stretch since the huge Katy Freeway overhaul, so maybe the exits are closer than that.

[Road Hog]

US 75 north of Dallas is the only Texas freeway that uses sequential numbering. The last exit before the Red River bridge is Exit 75, which is about 76 miles from the southern terminus in Dallas. So on average, this comes close.

[dgolub]

Also, the Belt Parkway and Cross Island Parkway combination.  The exits there are on a milepost system, but most people probably don't realize it.

Are they, though? Directional suffixes are used in several places, and a lot of the numbers are off by 1 or 2 from what they should be if they really were determined by mile marker. Also, exits 10 and 12 being missing from the seqeunce could be just as easily explained by those being the implied exit numbers for Plumb Beach and Jamaica Bay Riding Academy. Dunno why there's no 16, though.

The exits range from 1 to 36, and it's 36 miles long.  So maybe it's a modified milepost system.

[vdeane]

It could easily be coincidence though.  As mentioned, there's a block of numbers that should each be one lower than they are if it was mile-based.  That said, if NY was to convert, there's a decent chance the numbers would be left alone on these roads (though the Cross Island could just as easily get its own numbers in such a scenario).

[dfwmapper]

US 75 north of Dallas is the only Texas freeway that uses sequential numbering. The last exit before the Red River bridge is Exit 75, which is about 76 miles from the southern terminus in Dallas. So on average, this comes close.

From the southern terminus to Coit Rd., it is mileage-based, with Coit being 8B. It's just a shitty mess after that. The next exit is #20B Churchill Way (there is no 20 or 20A). There are 29 and 29A, 32 and 32A, and 38A, 38B, and 38C. Hoping they go to mileage-based numbers as more of it gets rebuilt.

[Duke87]

The Connecticut Turnpike (I-95), especially south of New Haven.

That assumes the exits are evenly distributed.  They are not.  There are a few longer gaps, but they're offset by the large number of interchanges in Bridgeport.

Depends on how strict your definition of "evenly distributed" is. No exit in Fairfield or New Haven counties is off from its theoretical mile-based number by more than 4. That said you are right - there is a bunching of exits in Bridgeport that compensates for a relative lack of them in Westport.

[mapman1071]

Also, the Belt Parkway and Cross Island Parkway combination.  The exits there are on a milepost system, but most people probably don't realize it.

Are they, though? Directional suffixes are used in several places, and a lot of the numbers are off by 1 or 2 from what they should be if they really were determined by mile marker. Also, exits 10 and 12 being missing from the seqeunce could be just as easily explained by those being the implied exit numbers for Plumb Beach and Jamaica Bay Riding Academy. Dunno why there's no 16, though.

The exits range from 1 to 36, and it's 36 miles long.  So maybe it's a modified milepost system.

(Exit 16)
(EB 84th Street/157th Avenue)
(WB 84th Street/156th Avenue (Flatlands Avenue))

[briantroutman]

This only goes on for a few miles, but seeing this stretch four times in a two-week period made me think of this thread.

There's a section of I-80 in Wyoming between mile markers 21 and 24 where three nearly identical diamond interchanges are spaced at nearly one-mile intervals Here's the Google satellite image, but it looks even more obvious in person as you crest the hill and see the three interchanges spread out in the valley before you.

I'll assume there was a reason to construct three interchanges so closely together in this desolate and uninhabited area.

[vdeane]

Probably because of two of those roads connect only to I-80 and nothing else.

[Bickendan]

I-84 in Oregon is an interesting hybrid. West of NE 102nd Ave, it's sequential (Exits 1-9). East of there, mileage based, but it lines up. starting with exit 10 at NE 122nd Ave. To make things interesting, traveling west from Idaho, while exit numbers and mileposts line up fairly well, the distance to Portland is off by two miles. For example, if you passing through Arlington (mp 137), you'd see this hypothetical mileage sign with these control cities:
The Dalles 52
Hood River 74
Portland 135

What happened here is that when the Columbia River Highway/Old Oregon Trail portion of I-80N (anything east of NE 102nd Ave) got its mileposts and exit numbers, it was in anticipation of the Mt Hood Freeway's construction. 80N's routing along the Banfield was just temporary and was meant to solely be US 30; 80N was supposed to start at I-5 at the Marquam Bridge and overlap US 26 along the Mt Hood Freeway to I-205, then north I-205 to the northern junction of US 30, accounting for the two extra miles.
(The Mt Hood was routed to run southeast from I-5 to between Division and Clinton streets, east to 45th, southeast to Powell [with an interchange with I-205's Yellow Book routing, the Laurelhurst Freeway], then east from there)

What this distills to is that the Banfield Freeway was meant to only be US 30, and I-80N was meant to join US 30 in Maywood Park/Parkrose. The sequential exits and mileage (rougly 8 miles) on the Banfield are US 30's; the mile based exits on the Columbia River Highway/Old Oregon Trail are I-84's. Incidentally, likely the only reason US 30 got exit numbers was because I-80N was there and Interstates needed exit numbers, given the Banfield leg of the Columbia River Highway was the second internal Oregon Highway US 30 follows (ORE HWY 2); the first is the Lower Columbia River Highway (ORE HWY 2W). US 26 got its exit numbers on the Sunset because it's the first internal highway it follows (not counting the shared portion of 101 before it was truncated from Astoria to Seaside), and OR 217 only has the Beaverton-Tigard Freeway alignment, so it got exit numbers... which are all .5 mile off.

[Kacie Jane]

Apologies for the minor bump, but I just realized that I-405 in Washington is an example of this that went unmentioned... (save for a bit of a gap north of SR 520, and then again at the north end).  Here's a quick exit list...

(0) - I-5
1 - SR 181
2 - SR 167
3 - SR 515 (SB off/NB on)
4 - SR 900 west/SR 169
5 - SR 900 east
6 - NE 30th St*
7 - NE 44th St*
9 - Lake Washington Blvd
10 - Coal Creek Parkway
11 - I-90
12 - SE 8th St
13A - NE 4th St
13B - NE 8th St
14 - SR 520
17 - NE 70th Pl
18 - NE 85th St
20A - NE 116th St (NB off, SB on)
20B - NE 124th St
22 - NE 160th St
23 - SR 522
24 - NE 195th St
26 - SR 527
(30) - I-5

*The city of Renton has a separate street grid with its own zero point, while the rest of the numbered streets (in Bellevue, Kirkland, and Bothell) all follow the county grid.

[mrsman]

I beleive there should be many areas that fit this bill, particularly as there are many areas of the Midwest and West where the urban areas were built on a grid, and the grid is designed to have a major arterial every mile, and likely a minor arterial every half mile.

CA-22 in Orange County has exits every mile from exit 7 (Golden West) to exit 12 (Harbor Blvd)

US 101 in the San Fernando Valley has exits every mile from exit 14 Laurel Canyon to exit 17 Van Nuys.  (There are also exits westbound only at Sepulveda one mile west of Van Nuys and eastbound only at Tujunga one mile east of Laurel Canyon).  There are also exits every mile from Balboa (exit 19) to De Soto (exit 26)

[freebrickproductions]

Exits 7 and 8 on I-565 are one mile apart. In fact, the overpasses at the two exits are also located right at the mile posts.