This freeway coming up from the southeast ends in mid-air, like the freeway from The Blues Brothers. Not even Evil Knievil would attempt this leap. Coming across the Betsy Ross Bridge from New Jersey, this strange and unusual interchange was constructed to be part of the “Five-Mile-Loop,” which would have connected US 1 with 90 and 95. This would have created an “inner loop” around the downtown core of Philadelphia. It remains unbuilt.

The freeway was originally accepted and slated for completion by 1975, but rising costs and political opposition caused the Pennsylvania Department of Transportation to halt funding for all new highway projects in July of 1977. It remains as some kind of weird monument, a prefigured bridge to nowhere.

As planned, the freeway would have bisected several neighborhoods, cemeteries and parks with a tremendous concrete freeway. As it is, the roads and bridges in Pennsylvania are in a state of serious disrepair, with a total repair bill of $6.5 billion. Too much. Not going to happen.

It’s a fairly accurate estimate though. They’ve got bumper mounted lasers and downward-pointing video cameras at PennDOT, and they survey every road and bridge in Pennsylvania every two years. That’s a lot of driving– over 40,000 miles of roadway. Completely surveyed and rated. In a huge database somewhere, presumably.

Enough driving to circumnavigate the globe one and a half times over. Every two years. Full road defect information.

Not enough money to make the repairs.

All of these roads constitute areas of impervious surface, with microclimates like little deserts. The total impervious surface area (ISA) in the United States, including rooftops, parking lots, streets and roads, within the lower 48 adds up to about the size of Ohio. That’s an area greater than the amount of wetlands found in the contiguous United States.

"ISA alters the shape of stream channels, raises the water temperature, and sweeps urban debris and pollutants into aquatic environments. It also increases the frequency and magnitude of surface runoff events. These effects lead to reduced biodiversity and degradation of wetlands and riparian zones. According to the article, these effects are measurable once impervious surfaces cover 10 percent of a watershed’s surface area." Colorado NPS Connection

With 10,000 miles of new roads being constructed every year, we continue to gradually pave over the United States. More impervious surface. More roads to maintain.

Crawling along the surface of the earth in lines, like ants.

Paving the lines over, then re-paving them after each winter’s freeze-and-thaw cycle seeps through the cracks in the concrete.

This image shows the city of Philadelphia. South of the river is New Jersey. You can see how the freeway that was never built would have cut right through the city’s core, largely for the benefit of commuters in outlying regions.

The United States has a lot of illumination, and as the home to the inventor of the electric light, that makes plenty of sense. It’s too bright to see the stars in most highly populated areas. It’s not just the astronomers who are complaining, although surely the migrating birds and sea turtles would complain if they could. Bright light is a stressor and has been shown to cause cannibalism in fowl.

It’s ironic because the streetlights are there for "safety" — in other words to keep people from killing themselves and each other. But what does it mean to have turned out the stars?

As much as 25% of electricity consumption (by far the #1 source of air pollution) in the United States goes towards lighting. We could save conservatively $2 BILLION a year and millions of tons of coal with more efficient use. A typical 100-Watt incandescent bulb could consume 750 pounds of coal and emit 2000 pounds of CO2 in one year – just one bulb! Choose energy efficient, downward directed, full cut-off, lighting fixtures in key locations only where needed. And please don’t aim them UP. Our Vanishing Night

Surely that makes sense. If the lights are bright and visible from orbit using spacecraft launched thirty years ago, then obviously there’s a lot of power being pumped into space.

My favorite lights right now are based on white LED lights. They’re ultra low power, don’t burn out, and throw a nice clear white light.

These days, most places in the world where people live, it’s easier to spot them at night. They light up. Most places. There are many significant exceptions. Most of these exceptions are enormous in area, in fact, the exceptions– the dark places– are the vast majority of the Earth’s land surface.

The water, of course, is the vast majority of the Earth. It’s completely dark, except for a handful of islands. Like England, Australia, etc.

Most of the earth is still dark at night.

I have to use heavy blinds to keep the light out of my windows at night, and I live in a city with less than half a million people in it. As far as cities go, that’s nothing. Chengdu lights up nicely as well, and although it’s not as bright as the island of Taiwan, the lush Sichuan Basin stands out, outlined in light.

I’ll be posting more excerpts from Earth At Night from NASA over the next day or so. If you can’t wait, click here (202kb jpg), or the image above.