Interstates with No Auxiliary Routes by FlaxmanR

Signs for this interstate at its origin on the south side of Chicago use Memphis as a control city, an interesting choice considering it runs out a good 140 miles north of Memphis. The longest continuous interstate with no auxiliary route, there are plans to extend it to Little Rock along the current US 67 corridor.

Interstate 17 has one of the highest endpoints of any interstate in the country, as its northern terminus at Interstate 40 lies at almost 7,000 feet of elevation in what Arizona city?

Joining I-90 on the southeast side of Rockford, Illinois, it does not have its own unique roadbed again until splitting off from 90/94 south of Portage, Wisconsin, after a 29-mile stretch (following I-94’s joining at Madison) that is the longest concurrency of three interstates in the country. Which interstate otherwise runs from Normal, Illinois to a point just shy of Wausau, Wisconsin?

Although it lacks auxiliary interstates, there are a number of smaller highways that serve similar functions for it, such as the SR 570 loop around Lakeland, and the SR 417 loop running from Celebration to Sanford. What interstate with one of the lowest numbers in the country connects the two major north-south interstates serving the state of Florida?

Exit 41 on Interstate 88 in Illinois is just a few miles from the small town of Tampico, while Exit 54 is just south of the town of Dixon. These two towns were notable in the early life of what famous American, for whom the tollway that spans much of I-88 was dedicated in 2004?

The original plan for the interstate included two auxiliary routes, astonishing for a 17.62-mile interstate that is the shortest in the contiguous United States and the only one to exist within a single county. What interstate, which has the second-highest two-digit number currently in use, never leaves Anne Arundel County, Maryland?

Interstate 27 has just two control cities across its entire length – Amarillo, where it intersects with I-40 at its northern end, and what other city at its southern terminus, the home of Texas Tech University?

For much of its length, it is known as the National Freeway, a reference to the old National Road which it parallels for some distance, as well as an appropriate name for an alternate route to the tolled Pennsylvania Turnpike. What interstate runs from I-79 south of Morgantown, West Virginia to I-70 at Hancock, Maryland?

Interstate 66 has an interchange with the George Washington Memorial Parkway just before it crosses the Potomac to enter the District of Columbia, appropriate as this section of the highway is also a “Memorial Parkway” named for a specific family. What last name, from her first husband, did Martha Washington – née Dandridge – have at the time she married George in 1759?

A somewhat rare case of an interstate designation taking over for a US highway with the exact same number, this US highway formerly ran from Miami all the way to Copper Harbor, Michigan. Since 2015, however, the US highway functionally does not exist as a separate entity between a couple miles south of the Wisconsin border and a point just north of Green Bay where it takes back over from the signed interstate. What number do the interstate and the US route (also notable as the US route that encompasses Lake Shore Drive in Chicago) share?

This interstate currently runs in two sections: the longer of the two runs between Interstates 76 and 80 in central Pennsylvania and is eventually intended to connect with the shorter of the two, which runs from the Pennsylvania border to the delightfully named town of Painted Post in New York. What interstate is the bane of numbering purists, as it lies between Interstates 79 and 81 but has a number well outside of them, breaking the convention of north-south interstate numbers getting progressively larger from west to east?

The newest signed interstate in the country is Interstate 14, which just began to receive its official signage on April 22, 2017. Although there have been talks of extensions, I-14 currently runs just 26 miles between the cities of Copperas Cove and Belton. This stretch of road most prominently serves what Texas-located U.S. Army installation, the largest military base in the world by area?