Tag Archives: Illinois

The diverging diamond interchange

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American interchanges can take many forms – see this field guide to highway interchanges from The Infrastructurist – including one called “the diverging diamond.” The goal is to provide better traffic flow from a road onto a highway through switching the lanes of traffic through the interchange area. That is, traffic entering on the right side of the road are then driving on the left through the interchange and vice versa.

Illinois Department of Transportation officials are considering this design, primarily being touted by Missouri officials, for an interchange in Naperville. See the design here and the background to the interchange here.

Cutting writing tests to save money

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The Chicago Tribune reports on Illinois’ plan to cut down on state writing tests for 2010-2011 to save $3.5 million. From the article:

[L]ate last month, the Illinois State Board of Education decided to eliminate the writing exam given to students in grades three, five, six and eight for the 2010-11 school year.

The 11th grade writing test still will be given because some universities require a writing exam of applicants, said state board spokesman Matt Vanover.

I wonder if this is a cut intended to draw outrage from citizens…who might then be willing to pay more toward education.

Additionally, federal statutes focus on reading and math and do not require a writing test. The article also notes that Illinois’ writing scores are typically poor.

Learning from the country’s largest urban solar plant

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The Chicago Tribune reports on a 40 acre solar power plant on the south side of Chicago, the largest urban solar plant in the United States. While the plant is not very big (generating 10 megawatts), some things I learned that shed light on the broader issue of clean energy:

-Benefits of a plant this size: “The solar plant generates enough electricity to power about 1,500 homes, and its clean power means less greenhouse gases are emitted, the equivalent of taking 2,500 cars off the road each year.”

-Perhaps Chicago is not a bad place to build solar facilities: “The sun in Illinois is more intense than in Japan or Germany, the world’s two largest solar markets.”

-On a national level: “Nationwide, there are more than 22,000 megawatts of large-scale solar projects under development, or enough to power 4.4 million homes.”

-“Green jobs” generated by building solar plants do not necessarily last over time: “Exelon’s West Pullman plant, for example, created about 200 jobs, but only during the six months of construction, he said. “It certainly wasn’t something that went on for years,” Lynch said.”

-Wind power is the main green energy for the near-future in Illinois: “Power companies in the state must get at least 25 percent of their electricity from green sources by 2025. Of that amount, 75 percent must come from wind, while only 6 percent must come from solar”

Summary: this plant has some clear benefits including cleaner energy and construction jobs. But there is a long way to go before solar plants, particularly in urban areas, can generate enough electricity at a reasonable price.