Transportation’s Exclusionary Measure “v/c” (volume/capacity) currently means vehicles/color.

When it became illegal to overtly exclude people of color from purchasing neighborhood homes, the powers-that-be excluded people more subtly using land-use codes and neighborhood covenants like single-family residential zones, minimum lot sizes, and minimum square footage.   In transportation, two extensively-used measures that exclude are v/c (volume/capacity) and LOS (Level-of-Service; derived directly from v/c).

The traffic engineering standard of v/c has been used for decades to describe how well a road can handle its traffic, and to determine when a road needs more lanes. Atlanta StreetAs v (actual traffic volume) approaches c (maximum volume at capacity) and v/c nears the value of 1, the road congests.  The practice is to reduce v/c below a specified maximum value (an “engineering standard”) by increasing the road capacity “c” with added lanes until v/c is below the standard, and will stay below it for the next 20 years.

Unfortunately, we have found that widening roads has a number of negative externalities: it induces driving, reduces walkability, increases VMT (Vehicle Miles Traveled), Induced Traffic 3increases crashes, and leads to sprawl densities, to name a few.  Also, the other modes of transportation have no competing standards; there are no standards for the loss of convenience and safety for pedestrians, cyclists, buses and transit users. So, when our government  mandates a standard  advancing vehicle movement, with no standards for the competing interests, we get more capacity for vehicles, and the collateral damage of other modes is immaterial.

This is inequity at its core. The demographic evidence of wealth and race as to who owns cars, drives cars, walks and rides buses is extensive. The geographic evidence of  communities through which highways and wider roads are constructed is also extensive. To top it off, the v/c standard is maintained for the peak hour, and data shows the peak-hour demographic is even more skewed to the wealthy white. And, the cost of reducing those last hundredths of v/c to meet the “standard” gets astronomical, especially per benefited driver — an analysis not required.  The result is the regressive exhaustion of transportation funds for a few car-driving Haves. In short, v/c = vehicles/color.

Finally, some cities and states are starting to realize just how inequitable this practice is, while some are adamantly upholding this standard in firm denial of its discriminatory effect. California has created two short videos that describe (1) the Problems with Level-Of-Service, and (2) the Benefits of VMT analysis, which is now all California is requiring in their Environmental Impact Reports. Although, these videos are not forthcoming on the discriminatory effects, they hint at them. Seattle is also reconsidering the use of LOS, along with other cities.

Oregon, however, is not there. The state’s Transportation Planning Rule (TPR) has nice language telling us that its purpose is to reduce our reliance on the SOV (Single Occupant Vehicle).

TPR Nice Language: “to: (a) encourage and support the availability of a variety of transportation choices for moving people that balance vehicular use with other transportation modes, including walking, bicycling, and transit in order to avoid principal reliance upon any one mode of transportation.” (660-012-0000(1)(b))

“…A key outcome of this effort is a reduction in reliance on single occupant automobile use, particularly during peak periods.” (660-012-0000(3)(c))

But, hiding in its bowels, the rule requires cities to meet v/c standards if land-use changes might degrade road performance standards.

TPR Real Purpose: “A plan or land use regulation amendment significantly affects a transportation facility if it would… (c)…(B) Degrade the performance of an existing or planned transportation facility such that it would not meet the performance standards…

The result is, cities find themselves on the hook for millions of dollars of capacity-adding projects for ODOT roads that will induce more VMT and sprawl – the opposite of the TPR’s stated purpose – and ODOT gets money from cities to pay for it. Albeit, the rule offers ways cities can prove they can accommodate the new trips with non-road projects if ODOT agrees — but the science is less firm, is not yet part of consultants’ recipe books,  and the rule gives ODOT a heavy hand, and they wield it.

I have also witnessed ODOT representatives in transit planning meetings holding adamantly firm to intersection v/c requirements, when every professional in the room knows that transit will move more people through the intersection per cycle, although fewer vehicles.  Another example of vehicles/color.

The current use of v/c as a standard hurts people, cities, and the planet.  As currently used, it needs to be vilified, and equitable performance measures need to be developed for transportation institutions.  The standards need to be focused on moving people, not vehicles.

The use of v/c can be turned on its head. As the California research and videos say, and Vision Zero research also verifies, the culprit is VMT.  If we shrink c for roads with high v/c, we inevitably shrink v, and the extra c (road capacity)  can be handed over to transit, walking, and biking for exclusive use. This reduces VMT and improves all other modes. This begins to rebalance a long history of prioritizing vehicles over people, and particularly over people of color. In conclusion, when your government agency uses v/c or Level-of-Service as their reason for a road or intersection “improvement,” let them know what that currently means – vehicles/color.

Author: Buff

Middle-aged white guy with a few degrees and 20 years in the transportation planning industry in Midwest and Northwest US cities. Email Comments To:

2 thoughts on “Transportation’s Exclusionary Measure “v/c” (volume/capacity) currently means vehicles/color.”

Comments are closed.