Top Ten Minnesota Fun Facts
Have fun reading these facts about the interstate highway system.
- A highway interstate highway system was first considered in the 1930s.
- President Roosevelt expressed interest in the idea as a way of providing jobs.
- President Eisenhower signed the Federal-Aid Highway Act of 1956 on June 29, 1956 in a hospital room (he was recovering from illness). The signed act created today's interstate system.
- Besides being designed to support automobile and heavy truck traffic, interstate highways are also designed for use in military and civil defense operations within the United States, particularly troop movements.
- The total miles of the interstate system in the U.S. is 46,837 (2004). In Minnesota, the total miles of U.S., state, county, city, and township highways is 141,687 (as of 2009).
- In Minnesota, and a few other states, there was actually highway princesses.
- Standards were also established for numbering the routes:
- Routes with odd numbers run north-south.
- Routes with even numbers run east-west.
- For north-south routes, the lowest numbers are in the west.
- For east-west routes, the lowest numbers are in the south.
- East-west interstate route numbers end in an even number. North-south routes end in an odd number.
- If the first digit of a three-digit interstate route number is odd, it is a spur into a city. If it is even, it goes through or around a city.
- Two-digit interstate highways are numbered according to direction and location. Highways running north-south are odd numbered, while highways running east-west are even numbered. The lowest numbers are in the west and in the south.
- Three-digit interstate highway numbers represent beltways or loops, attached to a primary interstate highway (represented by the last two numbers of the beltway’s number). Washington D.C.’s beltway is numbered 495, because its parent highway is I-95.
- To avoid duplication within a state, prefixes are used for the three-digit numbers. For example, I-80 runs through three cities in a state, so the routes in those cities would be numbered I-280, I-480 and I-680.
- For spur routes into three cities, the routes would be numbered I-180, I-380 and I-580. This system is not carried across state lines. As a result, two cities in different states along I-80 may each have circumferential beltways numbered I-280 or spur routes numbered I-180.
- There is also a system for numbering interstate interchanges, also known as exits. States do this numbering and can choose between two methods:
- The consecutive numbering system starts at the most western or southern point on each interstate route, and interchanges are numbered consecutively (so the first one is interchange #1).
- The milepost system numbers the interchange according to the miles counted, starting at the most western or southern point. An interchange occurring between mileposts 4 and 5 would be designated interchange #4.
- Minnesota has 20,205 bridges that are more than 10 feet long.
- Mn/DOT has approximately 780 trucks for snow removal and 46 reserve trucks. The reserve trucks provide backup in case of breakdowns.
Compiled from the following Web sites:
Mn/DOT's Traffic, Safety and Technology office