Getting there

Following up on a discussion I had recently, I would like to present the definitive essay on the Interstate Highway System (IHS). By definitive I mean researched in a thoroughly cursory manner and embellished by amplifications, selective use of data, statistically unsupportable extrapolations and my own opinions. That is what definitive means, right?

Like most important parts of 21st century life, the IHS was developed during my lifetime. I saw numerous pieces of it evolve from plans to concrete. When I moved to Philadelphia, one of the first things I read in the Inquirer was a humorous essay about I-95 in the Sunday Magazine, which is no longer published. It was done in a Q&A format and the first question was simply, "What is I-95?" Answer: "I-95 is a highway that runs from Maine to Girard Avenue and from the Philadelphia Airport to Florida."

The IHS was born in the aftermath of WWII from the mankind's typical instinct to develop strategies to fight the previous war. Then-President Eisenhower, a military guy by trade, decided he needed a system of limited access roads (as in, have entrances and exits rather than intersections with streets) with which we could move troops and equipment by road from, say Los Angeles to Washington DC without stopping at 15,000 traffic lights on the way. Building began in the early 1950s and continues to this day.

Although many parts of the Interstates have names, (the entire system is named after Eisenhower), most are known only by their number. The numbering system was designed to complement the US Highway system, keeping odd numbers going North-South and evens East-West, but reversing the direction of numbering. For example, I-95 is the easternmost interstate and US 1 the easternmost US route. The only oddities in this system are in the middle of the country, where they skip numbers to avoid having, for example, both US Route and Interstate 60 in the same state. We the people are presumed to be unable to distinguish one from the other, yet another way the government restricts our first amendment right to worship the religion of automobile usage.

Also, because the country irregularly shaped, not all the roads go all the way from east to west. I-90, for example, starts  in Massachusetts, but when the Great Lakes push the northern border south, it merges with I-80, only to reappear in Chicago and continue to Seattle.

The numbering of the main routes is a model of simplicity compared to the numbering of the connecting routes. In this area, the main connectors are I-476 and I-676. In Pennsylvania, both of these connect I's 76 and 95, but one runs east-west and the other north south. To make things more confusing I-476 also connects 276, 78, 80, 84 and 81. And east-west 676 disappears at the Delaware River and reappears in New Jersey, running north-south and connecting 295 and another piece of 76.

The code for numbering connectors, which is more guidelines than an actual code, are that connectors that intersect interstates at both ends get even numbers and those that don't have odd numbers. This code is violated frequently depending on convenience. New Jersey's version of 676 has no connector on its north end, but I-195, the road to Great Adventure in New Jersey, is more the way it should work.

The IHS was build with either willful ignorance or blatant disregard of the consequences of road building. The first rule is that new roads attract new traffic, and the consequence is that they almost never alleviate traffic problems. The most common mistake is the notion that building interstates to funnel traffic into a city are counterproductive. Roads that connect, for example, northern and southern suburbs to an urban core also allow people to commute from the north to the south as well. Locally, the Schuyllkill Expressway, now I-76, was built solely for the purpose of bringing people from the suburbs into Center City. But it didn't take long for people to figure out that they could also use it to commute from South Jersey to King of Prussia. Hence more traffic than anticipated.

Even more tragic is when the interstate merely passes by a city or town, cutting it off from the traffic and starving it economically. But that's a long, sad, complicated story and not one I care to expound on right now.