Straightest highways

[tolbs17]

These are what I can think of.

US-70 from Cove City to New Bern

I-74 from Maxton to I-95.

US-17 (Elizabeth City bypass)

US-13/NC-11 from Greenville to Bethel.

Pretty much any highway east of I-95 in NC is a lot more straight.

[TheHighwayMan3561]

There are other examples that make these roads look like mountain pass routes.

[SkyPesos]

I-80 west of SLC

[Big John]

I-41/94 from the Milwaukee/Racine County line to the Wisconsin/Illinois state line.

[dlsterner]

I think that it would be a great experience for the OP to take a road trip out to the Midwest, or to the Plains states, and see how the roads differ out there compared to what he is used to where he lives.

Really, these North Carolina examples are perfectly straight for only a few miles each.  Even combined, probably less mileage than the I-80 in Utah example cited earlier.

Off the top of my head the Lake Pontchartrain causeway is twenty-plus miles (although it may be cheating to use a bridge or causeway).  And if memory serves me, isn't there a road with 40-ish miles in (I think) North Dakota?

[CoreySamson]

I-80 between Lincoln and Grand Island in Nebraska is more or less straight for almost 80 miles.

[skluth]

US 136 runs about 70 miles in a straight line west of Rantoul IL

[Sapphuby]

US 136 runs about 70 miles in a straight line west of Rantoul IL

I was also thinking this! Really started to wonder if anyone was going to point this out, it's straight as a board. Also, there's a segment of U.S. 36 in Illinois that's straight as well for 56 miles, from just east of Casner to 2.8 miles west of Chrisman. If we were to not include the 2-5 degree turn west of Chrisman, then by all means it's a straight-ish line for a bit under 62 miles.

[skluth]

US 136 runs about 70 miles in a straight line west of Rantoul IL

I was also thinking this! Really started to wonder if anyone was going to point this out, it's straight as a board. Also, there's a segment of U.S. 36 in Illinois that's straight as well for 56 miles, from just east of Casner to 2.8 miles west of Chrisman. If we were to not include the 2-5 degree turn west of Chrisman, then by all means it's a straight-ish line for a bit under 62 miles.

I'm sure there are similar, if not longer, straight roads in the Great Plains region. But I went to my Navy weather school at Chanute AFB in Rantoul and I was surprised at how boringly straight the roads were in Illinois even though I grew up in Wisconsin.

[Sapphuby]

US 136 runs about 70 miles in a straight line west of Rantoul IL

I was also thinking this! Really started to wonder if anyone was going to point this out, it's straight as a board. Also, there's a segment of U.S. 36 in Illinois that's straight as well for 56 miles, from just east of Casner to 2.8 miles west of Chrisman. If we were to not include the 2-5 degree turn west of Chrisman, then by all means it's a straight-ish line for a bit under 62 miles.

I'm sure there are similar, if not longer, straight roads in the Great Plains region. But I went to my Navy weather school at Chanute AFB in Rantoul and I was surprised at how boringly straight the roads were in Illinois even though I grew up in Wisconsin.

I've been on most of the U.S. 36 portion I described (from IL 130 to Casner), and there's pretty much nothing out there. Other than the Casner turn and the industrial park, there's just nothing to look at unless you're interested in corn.

[ozarkman417]

A 256km stretch Saudi Arabia's highway 10 is often featured on media sites as the straightest highway in the world. Though, by looking at satellite imagery of the highway, it appears they are upgrading (or have already upgraded parts of) the two lane highway to a divided four lane, which has introduced some shallow curves.

[7/8]

There's a 25 mi / 40 km straight stretch on M-28 in the UP:
https://en.wikipedia.org/wiki/M-28_(Michigan_highway)#Seney_Stretch

There's also a 91 mi / 147 km straight stretch on the Eyre Highway (#1) in Western Australia:
https://en.wikipedia.org/wiki/Eyre_Highway#Western_Australia

[thspfc]

I-80 between Lincoln and Grand Island, NE

[ran4sh]

The longest stretch of straight road I've seen in Georgia is an about 18-mile length of I-20 west of Augusta.

[thenetwork]

ISTR I-39 North of I-80 in Illinois a pretty straight-as-an-arrow freeway whn I drove it in the 90s.

[adventurernumber1]

Although there's curves here and there I-75 through the Everglades seems to be largely composed of several long segments of straight road.

A stretch of US 27 in the area (from a little bit north of I-75 to a little bit south of Belle Glade) is also straight for around 27 miles (unless I am failing to detect any small curves on my phone).

US 41 through the eastern part of the Everglades is in the same situation as I-75 (a few curves, but several long stretches of straight road), but US 41's trek through the western part of the Everglades is much more curvy.

There is also the stretch of straight road on US 19/US 98 that clocks in at about 21 miles (unless you're going southeastbound in which case there's a slight curve) from just west of FL 121 to Chiefland.

I'm sure there's plenty more of examples like these in Florida, which seems to have a good bit for a southeastern state.

[MikeTheActuary]

Found a list: https://www.dangerousroads.org/around-the-world/our-lists/3759-the-10-longest-straight-roads-in-the-world.html

1.  Saudi highway 85: 693mi
2.  Saudi highway 10: 158mi
3.  Ruta Ciduad Mariscal Estigambia - Mayor Pablo Lagerenza in Paraguay: 128mi
4.  ND 46: 121mi
5.  Mitchell Highway (B71), NSW Australia: 118mi
6.  US 54 Seward, TX - Dalhart, KS: 108mi
7.  Carretera Federal 1, BCS, Mexico: 105mi
8.  US 136, Illinois: 102mi
9.  Saudi highway 50: 95mi
10. US 83, North Dakota: 92mi
11. Eyre Highway, Australia: 91mi
12. SK 33, Stoughton-Regina: 87 mi
13. Ruta Procincal 26, La Pampa, Argentina: 82mi
14. I-10, western Arizona: 82mi
15. SL10/SK52:  81mi

BTW, the Dangerousroads website is an interesting one, for those who haven't discovered it yet.

Edit: Looking at a few of the roads, it looks like Dangerousroads is tolerating a few minor changes in heading that might not be tolerated within the precision desired by the OP.  For example, ND46 has a few minor jogs at a couple of river crossings

[Bitmapped]

With the exception of a brief realignment for the Williamstown "bypass," old US 30/US 30N was arrow-straight for 41 miles starting just west of Upper Sandusky, OH: https://goo.gl/maps/18LH6jCR2iTko1Uc7

[tolbs17]

I-95 from Eastover to Dunn feels so straight. So does from Kenly to Smithfield. Those were like the first ever segments of the highway to be built though. I think from Lumberton to St Pauls can also qualify.

Newer highways tend to be more curvy.

[SkyPesos]

I-95 from Eastover to Dunn feels so straight. So does from Kenly to Smithfield. Those were like the first ever segments of the highway to be built though. I think from Lumberton to St Pauls can also qualify.

Newer highways tend to be more curvy.

Yes... straight...


Have you checked out any of the examples posted upthread of roads in the plains states yet, for what a straight road really looks like?

[tolbs17]

I-95 from Eastover to Dunn feels so straight. So does from Kenly to Smithfield. Those were like the first ever segments of the highway to be built though. I think from Lumberton to St Pauls can also qualify.

Newer highways tend to be more curvy.

Yes... straight...


Have you checked out any of the examples posted upthread of roads in the plains states yet, for what a straight road really looks like?

Yes. Usually continously long, with no curves. The midwest has a handful of them.

[dlsterner]

I-95 from Eastover to Dunn feels so straight. So does from Kenly to Smithfield. Those were like the first ever segments of the highway to be built though. I think from Lumberton to St Pauls can also qualify.

Newer highways tend to be more curvy.

Yes... straight...


Have you checked out any of the examples posted upthread of roads in the plains states yet, for what a straight road really looks like?

Claiming that "I-95 in North Carolina is straight" is like claiming that "Illinois is not flat".

[CNGL-Leudimin]

No way there could be a 1115 km straight! I've looked at that Saudi road, and I'm unable to get any straight section longer than about 20 km.

[MATraveler128]

I-95 north of Peabody, MA to the NH state line is relatively straight. Probably one of the straightest highway in the Northeast.

[Sapphuby]

I-95 north of Peabody, MA to the NH state line is relatively straight. Probably one of the straightest highway in the Northeast.

If you mean slight curves every 5 or so miles, then yeah, it's relatively straight. If you mean bullet straight, I-95 isn't going to cut it.