Context-Sensitive Access Management

http://en.wikipedia.org/wiki/Access_management)

By Dom Nozzi

Wikipedia defines “access management” as “…the regulation of interchanges, intersections, driveways and median openings to a roadway. Its objectives are to enable access to land uses while maintaining roadway safety and mobility through controlling access location, design, spacing and operation. This is particularly important for major roadways intended to provide efficient service to through-traffic movements…” (

 

As a planner in FL for the past 20 years (where “growth management” is essentially a code word for ensuring that new development does not delay or slow down cars), I observed that “access management” was touted strongly—to the detriment of pedestrians, bicyclists, and transit users. And the overall quality of life.

 

Detrimental because speeded up car traffic (particularly “through” traffic) is toxic to safe, comfortable, convenient walking, bicycling or transit use. Common access management tools, such as longer block lengths, funneling car trips onto fewer and therefore larger roads, and less road crossings, are obstacles for pedestrians, bicyclists or transit users.

 

Tellingly, because we operate in the “Happy Car” paradigm, even pedestrian, bicycle and transit advocates have become advocates of access management, even though such management typically undercuts pedestrian, bicycle or transit travel.

 

The Zero-Sum Game

Design for motor vehicle transportation is a zero-sum game. Almost inevitably, when conditions for cars are “improved” (“speeded up,” “made more efficient,”, etc.), conditions for all other forms of travel (bike, pedestrian, transit) are degraded.

 

An enormous part of our problem here is what economists call “The Barrier Effect,” which is a principle stating that certain things create barriers to the use of something else. In this case, the Barrier Effect is caused by cars. Single-mindedly designing our transportation system for cars creates substantial barriers for those wishing to use transit, walk or bicycle. Who in their right mind, for example, would feel safe bicycling on a six-lane road?

 

In other words, whenever we modify a road to create “efficient” or “free-flowing” or “less congested” roads (usually by widening the road or adding turn lanes), the Barrier Effect means that we are simultaneously and unintentionally making it harder to walk, bicycle or use transit. A classic “zero-sum” game where, when cars win, all other forms of travel lose. It means that road “improvements” for cars recruits even more motorists who were formerly walking, bicycling or using transit.

 

A self-perpetuating vicious cycle of unintended consequences. One where spending millions of dollars of our tax money on road widenings makes us our own worst enemy.

 

The Need for Context-Sensitivity

The first task for a planner seeking to determine appropriate design is to first determine where in the community the design will occur. Once this is known, the design can be tailored to be “context sensitive.”

 

One must know if the design is to be applied in suburban/drivable locations, or urban/walkable locations. If the former, conventional access management tactics tend to be appropriate, as the imperative is to minimize car travel delays and maximize car speeds.

However, in urban/walkable/compact/mixed-use locations, the pedestrian is the design imperative. In such locations, it is therefore essential that slow-speed (and “attentive motorist”) design be emphasized to maximize pedestrian comfort and safety. Access management tends to undercut such a design objective, because motorists can drive faster and less attentively when access management is successful.

A quality pedestrian environment must include relatively short block lengths, as well as mid-block crossings and cross-access within blocks. Again, access management tends to undercut these essential design tactics in walkable locations.

 

Speaking as a bicycle commuter, I tend to find a reduction in driveways (another common access management tool) to be an inconvenience for bicycling. I understand the safety problems associated with too many driveways, but we shouldn’t forget unintended consequences.

 

When the words “safety” and “efficient” and “mobility” are used in the field of transportation, such words tend to be euphemisms for higher speed, unimpeded car travel. And the last thing a healthy, low-speed, pedestrian-friendly downtown needs is faster, unimpeded, through car travel. Higher speed (“efficient”) car travel in a downtown (not to mention excessive, under-priced off-street parking) drains the lifeblood out of a downtown.

Again, be careful about where various designs are applied. Avoid “one-size-fits-all” solutions. What is beneficial for higher-speed suburbia is almost always detrimental to lower-speed walkable downtowns, where transportation choice must be emphasized. 

 

Be sure you are context-sensitive—that you are applying the right design tools to the appropriate locations of the community.

 

A Solution

A solution to this dilemma, then, is to establish zones in your community. In your suburban (drivable) zone, conventional access management tactics can be employed appropriately. In your more compact, urbanized, higher-density (walkable) zone, access management tools should be avoided.

 

The walkable zone (or zones, if the community intends to create additional walkable locations other than in its downtown) should be exempted from access management. More appropriate tools, such as short block lengths, connected streets, mid-block crossings, on-street parking, cross-access within blocks, and narrow streets, should be employed. Unlike in the suburbs, in the walkable zone it is desirable to slow car traffic and obligate motorist attentiveness.

 

One-size-fits-all, when applied to such strategies as access management, is detrimental to the diversity of lifestyles and transportation choices found in healthy cities. Let the suburb be a suburb. But let the city be a city.

_________________________________________________

Visit my urban design website read more about what I have to say on those topics. You can also schedule me to give a speech in your community about transportation and congestion, land use development and sprawl, and improving quality of life.

Visit: www.walkablestreets.wordpress.com

Or email me at: dom[AT]walkablestreets.com

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Filed under Bicycling, Sprawl, Suburbia, Urban Design, Walking

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