Make Impermeable Roads Permeable?

Innovators: Better Roads Ahead

Researchers at Washington State University discuss problems involved with the construction and use of roads in urban settings. Once a city is paved and the quantity of permeable land is reduced, pollution builds up on roads, awaiting the next heavy rainfall to wash it away. Since this rain is then unable to reenter ground water due to the pavement, it instead flows into sewers and directly into waterways. This inhibits the ground from filtering the pollutants and flushes large quantities of the pollutants into rivers and streams in a short time. These researchers purpose a new type a pavement that would allow for water to permeate through it and enter the ground, helping to mitigate the issue.

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Lombard Street: San Francisco’s Most Popular Road

Current Day Lombard Street // Image from: http://sanfranciscoforyou.com/wp-content/uploads/2010/03/lombard-street.jpg

Guidelines is a monthly newsletter of the San Francisco City Guides webpage containing articles about San Francisco’s history. One article in particular focuses on Lombard Street, a road constructed in 1922 with 8 turns, a 16% steep grade, and 250 steps per side. This is one of the steepest and curviest streets to date and upon construction immediately posed problems for the growing urban city. In this article, Susan Saperstein writes about how the city paid for the street on the condition that the residents maintain the plantings. As would be expected, neighbors complained and argued about the management of the plants and shrubbery. On top of this, the plants did not hold the soil back and erosion problems arose. However, it was soon discovered that hydrangeas have the ability to prevent erosion and these plants soon lined the 250 steps of Lombard Street. Today this road is a popular tourist destination and illustrates the marvels of urban road planning and environmental wonders.