Monday, December 05, 2016

Jeff Gahan's predictably wasted opportunity to civilize Vincennes Street using Jeff Speck's sensible plan.

This text is pasted from Jeff Speck's landmark New Albany streets study, and now serves to remind us that from a glorious potential starting point of ribeye, we're left with a tiny puddle of fatty stew meat.


A Limited Mandate

The conclusions from this exercise are clear: downtown New Albany has the potential to become much more crowded with vehicles than it currently is, and the best way to protect against this overcrowding would be to reduce the Supply of downtown lanes to a number that is no greater than the current Demand.

However, as dramatic as this recommendation would sound, it actually has a very limited impact, since so few of New Albany’s streets are more than two lanes wide.

As will be discussed ahead, two-way traffic is superior to one-way traffic for both safety and city vitality, and a conversion of many streets back to two-way traffic will be recommended. This means that only those streets of more than two lanes are candidates for reduction. Within the study area, that condition applies to significant stretches of only the following streets: Vincennes, Market, and Spring.

Within the study area, Vincennes is the easiest street to discuss, because it contains a strange extra northbound lane, creating a 3-lane capacity on a road carrying only slightly more than one lane’s worth of traffic. It also has a massive 5-lane cross-section at its intersection with Main Street, despite its low car counts. Eliminating the extra northbound lane and the unnecessary right-hand turn lane at the Main Street intersection will result in a safer street that is still sized well beyond its current volume would demand.

Vincennes Street

Vincennes Street’s asymmetrical section contains an additional northbound lane that is not justified by traffic demand.

Current Condition

From half a block north of Spring Street to Main Street, Vincennes Street consists principally of a three-lane section, with additional right-hand turn lanes inserted at Spring Street and Main Street, and an additional southbound lane added at Main. This 3-lane section is striped with two lanes northbound and one lane southbound, as if the northbound flow were dominant, but it is not. Hourly traffic counts on Vincennes peak at 490 north of Main, 812 north of Market, and 654 north of Oak.

Vincennes Street is clearly oversized for its traffic. At no point do car accounts approach the number that would require a third lane. This condition is supported by the fact that the third lane, rather then being striped for left turns, merely provides northbound redundancy with no southbound counterpart.

Acknowledging that a two-lane section is ample south of the busy Spring Street intersection allows the extra northbound lane to be replaced by a wider parking aisle on that side, holding angled parking instead of parallel. Given that Vincennes is a desired bike route, this parking should be back-in, and sharrows should be placed in the roadway.

As it approaches Main Street, the tapered cross section gains additional width that should be put to used as a center turn lane, with other lanes (including the parking lane) widening slightly in order to use up the extra asphalt.


From Division to Stone, restripe Vincennes to include 8-foot parallel parking on its western curb and 17-foot back-in angle parking (at 60 degrees) on its eastern curb. South of Stone, as the street widens, insert a 12-foot left-hand turn lane, and broaden the parking bays to 10 feet and 18 feet respectively. Insert sharrow markings in roadway near each intersection.

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