Sustainable Land Development Today - November/December 2008 - (Page 40)

INNOVATION Go with the “Flow” In many instances, great opportunities for a more sustainable design are overlooked. By Rick Harrison When looking at the various methodologies associated with sustainable development that are discussed and implemented today, there are a number of important issues that are not given the attention they deserve. One, often-overlooked aspect of sustainable-neighborhood design is how vehicular-traffic flow* impacts safety, quality of life, residents’ pocketbooks, and the environment. In fact, it is the lack of focus on such flow patterns that has been instrumental in widespread perception that “sprawl” is the root of our ills today. The goal of efficient traffic flow is to reduce the time it takes to travel through a development from its entrance point to the destination. If we can reduce by a few minutes the travel time for an individual who lives, shops or works within the development, the benefits in energy conservation and time savings can be enormous over time. This case study explores the point. site, which had thick woods and steep slopes. By focusing on how to improve the traffic flow, ways became readily apparent to dramatically improve the plan, maintain the needed density, and preserve woodland area and green space, all at the same time. (figure 2) Figure 2 Another Way to Get There Early in 2008, my firm began the replanning of a site in Minnetrista, Minnesota, a suburban town about a half hour west of downtown Minneapolis. An earlier plan (figure 1) was one of a series of proposals that was rejected by the city council as being too dense for the The initial, cookie-cutter design relocated the north half of the existing Street B so that the current residents to the south would need to drive to the new connections every day, either to the west or to a new intersection to the east. The reconfiguration of Street B was solely due to a request by the civil authority to increase spacing. The construction of the new streets through the heavily wooded and steep slopes would consume land that could otherwise be used for homes and yard space. At the initial meeting with the local officials, the idea of keeping streets exactly where they were with close intersections became an issue. The concept of re-routing the east cul-de-sac to the existing street on the south was suggested. In a typical planning situation most consultants would simply comply with the request, no questions asked. But let’s look at the ramifications from a “flow” perspective. The reroute (fig. 3) would have included a private drive Figure 1 down steep slopes, which would be hazardous during winter weather when it is covered with snow and ice. Further, the loss of a unit and the increased construction costs would be spread among the Figure 3 other 35 residents. But there is a more critical impact. Traffic flow would be rerouted a much greater distance, which creates problems– not the least of which is the threat to pedestrian safety – just to get out onto the same county road. The increased average distance for the residents on the east cluster is 1,750 feet — one-third of a mile. The increased distance is actually twice that, since what comes in must also go out. The original plan had seven homes, which had a direct and easy drive to the county road, but the residents would need to pass eight additional driveways (points of conflict) on the way to their first street intersection. Undoubtedly, they would be in a hurry and just slow down to crawl through the 90 degree turn at the intersection at Street B then accelerate back up a hill past another intersection serving fourteen more homes and slow down to stop at the exit intersection. The increase in time, exposure to accidents, and energy consumption per trip is enormous. According to a study by the county, the average home in the area made ten trips a day, so each home needed to exit the property and re-enter ten times. This equates to twenty, onethird-mile trips per day – or 6.62 miles per day, per house. But there are seven homes affected. That’s an additional 40 November/December 2008 Sustainable Land Development Today

Table of Contents Feed for the Digital Edition of Sustainable Land Development Today - November/December 2008

Sustainable Land Development Today - November/December 2008 Contents Our Voice Editorial Board SLDT Resources The BottomLine Go Forth and Tread Lightly on the Land It’s About Name Recognition Managing Risk in the Sustainable Building Frontier Industry Spotlight Achieving Sustainable Land Development Worthy of Recognition Stormwater Wastewater Erosion Control Innovation Classifieds Advertiser Index Last Word

Sustainable Land Development Today - November/December 2008

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