If you keep going straight . . .

[Streetman]

...
I've interpreted "keep going straight" to include following the road when it curves and becomes another road as presently constructed.
...

Yes, of course you could go much longer distances on one road that bends and twists, but I thought it was pretty amazing how straight that Hamden-Hartford route was. You could follow Main St. in Hartford past the straight stretch and it will take you "straight" onto US-44 until just over the state line in Millerton, NY where that route turns left at a T intersection.

[pianocello]

Has anyone done this one yet? You can have an almost day-long journey between Barstow, California and the Platte River in Nebraska without making a single turn: https://www.google.com/maps/dir/34.8860742,-117.008774/37th+Road+%26+141+Road,+North+Osceola,+NE/@38.2288548,-115.5003971,5.17z/am=t/data=!4m14!4m13!1m5!3m4!1m2!1d-97.4651945!2d35.4887527!3s0x87b217967560922f:0x42ef4641f7bbbdf2!1m5!1m1!1s0x8790bd4784a2643f:0xc4d1a4c5aec4671f!2m2!1d-97.598237!2d41.3310456!3e0?entry=ttu

Looks like you're turning off in Wichita to get to I-135. If continue straight on the Kansas Turnpike instead, you make it to at least the I-70/35 interchange in downtown Kansas City (about an hour shorter, but still impressive). But if you consider "going straight" at that interchange to follow I-35 north, you make it as far as I-465 in Indianapolis by way of I-35, I-80 and I-74.

[debragga]

https://www.google.com/maps/dir/31.9828422,-98.0339309/29.8531895,-97.7209489/@30.9659877,-98.6486299,8.04z/data=!4m19!4m18!1m15!3m4!1m2!1d-97.6892212!2d30.0320955!3s0x8644aeadd904df9b:0x35d048a4a17f9eec!3m4!1m2!1d-97.688376!2d30.009515!3s0x8644a95b22df27b3:0x2192f76831cd9569!3m4!1m2!1d-97.6842531!2d29.9887845!3s0x8644a971aa87e41f:0xe1c944875ac0799e!1m0!3e0?entry=ttu

Hico to outside of Lockhart in TX, 166 miles. US-281 -> US-183 -> 183A toll road -> back to US-183 -> 183 toll road -> US-183 a third time, where it eventually becomes the service road for TX-130 toll road -> TX-130 service road after US-183 splits off

[Quillz]

I can get from my house to Prudhoe Bay, AK with minimal turns. US-101 to I-405 to I-5 to US-97 to BC-97 to YT-2 to AK-4 to AK-2 to AK-11. There would be a freeway interchange, an off-ramp, then it's mainly just staying in one lane as I travel northward. There would a hard turn onto AK-2 and then AK-11. Not sure of the exact mileage, at least 2,000 miles or so.

[vdeane]

^ There are a few turns to stay on US 97 and BC 97.  AK 2 to AK 11 was straight through last I checked; AK 2 to Manley has to turn to stay on the route.

[debragga]

I found an interesting one that actually loops in on itself. It's TX-205 from Lavon to Terrell via Rockwall and McLendon-Chisolm, then it continues as FM 148 to Talty, then it's FM-1641 to Forney, and the last stretch is as FM-548 to end back at SH-205 near McLendon-Chisolm. 43.5 miles and on a map it looks like the Big Dipper:

https://www.google.com/maps/dir/33.0222215,-96.4563329/32.8189425,-96.3522867/@32.8434966,-96.6182523,10.38z/data=!4m24!4m23!1m20!3m4!1m2!1d-96.4632261!2d32.9530265!3s0x864c01a65bc13fcf:0xb68611615f6c9866!3m4!1m2!1d-96.3416376!2d32.7060682!3s0x86494dc63aedef51:0x390311ee21ebfa3f!3m4!1m2!1d-96.4047415!2d32.6999822!3s0x86494d2c2df5776b:0xe34861f51aa7fdf9!3m4!1m2!1d-96.4378128!2d32.7294654!3s0x864eb29ce828b1a3:0xb46141ccdc45831b!1m0!3e0!5m1!1e1?entry=ttu