Street design manuals

Yesterday's New York Times has an article, "City Issues Street Design Manual," on NYC's new street design manual, published by the NYC Department of Transportation.

An incomplete street, NYC Department of Transportation Street Design Manual.

There is no question that the new New York City Street Design Manual is far more detailed and therefore likely more useful than the equivalent in DC, the DC Public Realm Design Handbook. The NYC manual is more descriptive and prescriptive. The DC manual is from 2007, and it doesn't include deep, specific details in the way that the NYC manual does.

For example, the DC manual outlines a hierarchy of streets, but doesn't provide detailed descriptions and a framework for treating each type of street.

Hierarchy of streets diagram from the DC Public Realm Design Handbook.

One of the things that I believe is essential to sound planning is the creation of strong planning frameworks (processes) that make sure you cover "everything" and that you go through the process thoroughly, with the endgame being creating a robust result.

So often, when I participate in DC planning processes (either through the Office of Planning or the Department of Transportation) or when I read about other planning projects that I can't get to, I don't feel as if there is a robust framework being used. That doesn't mean that the planning process is horrid, but it does mean that it's flawed and likely to generate an incomplete result.

(And as I wrote in the comments to another entry, when I do commercial district revitalization planning myself, in other communities, I am working to build the ultimate master framework, and we do a wide variety of interviews, observation processes, reviews of a wide variety of reports, media, and other materials, evaluations of competitive commercial districts, etc., so that we uncover as many issues as possible, whether or not the issues were originally identified within the scope of work.)

How the street pictured above would look after applying the urban design review process prescribed in the NYC Department of Transportation Street Design Manual.

The NYC Street Design Manual provides a perfect example of a better way to do things in its highly detailed process for design review (on page 38 of the manual and the form is printed in Appendix A). To my way of thinking, it covers just about everything (except for one thing, utilities):

Street Context

- History and Character
- Land Use
- Network Role
- Major Sites
- Street Width
- Materials, light, and furnishings
- Application
- Divergence
- Pilot Treatment

Street Operation

- Walking
- Bicycling
- Motor Vehicles
- Transit
- Trucks/Freight
- Accessibility
- Curbside conditions
- Public space
- Drainage
- Street Cuts

Greening

- Street trees
- Greenstreets and vegetation
- Stormwater conditions
- Flooding
- Maintenance
- Permits
- Partners

Note in the section on street operations that "divergence" is listed as a factor for consideration. That means that if there are to be exceptions or variances from standards, they must be justified and approved. There are (perhaps only a handful of) times when variances make sense in terms of exceptions from "one master way" of doing things, but many DC laws don't provide a way to deal with this (for example replacing trees on the North Hall Plaza of Eastern Market, when the plaza is used for craft sales and should have been all hardscape to begin with...). Zoning does provide a process for granting changes (special exceptions, variances, and other processes).

Another good resource along these lines is the Smart Transportation Guidebook co-produced by the States of Pennsylvania and New Jersey.