Revised October 17, 2003
| What is the
Growth Management Act (GMA)?
Management Act was adopted in 1990 to manage the rapid development in
the state. Counties and cities are required to create 20-year plans
that designate urban growth areas for projected development to avoid
urban sprawl and to protect natural resources. The Growth Management
Act also requires local governments to ensure that transportation and
other essential public facilities be at adequate levels before any development
project can be approved. For more information about the Growth Management
Act, log onto: http://www.ocd.wa.gov/info/lgd/growth/law/index.tpl.
Also relevant to
the issue of concurrency is Vision 2020, the Puget Sound Region's goals
and plan for 20-year growth. It has been developed by the Puget Sound
What is concurrency?
Concurrency is the requirement that infrastructure
to support development must be planned and funded before development
can be improved and built. Such infrastructure includes facilities for
water, sewage, and transportation. This study is concentrating on the
transportation element of concurrency.
The Washington State Growth Management Act requires that public transportation
(as well as the other infrastructure facilities be in place within six
years from "the time of development" to accommodate the impacts of new
development. Local governments planning under the GMA must establish
Level of Service (LOS) standards for their transportation system, primarily
roadways, in their comprehensive plans. They may permit new development
within their jurisdictions as long as the transportation infrastructure
will sustain the required LOS or the developer mitigates circumstances
to achieve the LOS.
What is the Eastside Transportation Concurrency Study?
The Eastside Transportation Concurrency Study is a two-year assessment
of how concurrency is managed in the four Eastside cities of Bellevue,
Redmond, Kirkland, and Issaquah. The study will evaluate the extent
to which meeting concurrency requirements assists the four cities in
complying with the intent of the state's Growth Management Act and the
region's 2020 objectives. The study will investigate alternative measures
of transportation concurrency and suggest what changes, if any, to state
and local laws would provide more effective ways of dealing with concurrency
The city of Bellevue is managing the project on behalf of the four
Eastside cities, utilizing $250,000 in funding from the state legislature.
The study is being undertaken by a University of Washington team led
by the Washington State Transportation Center (TRAC) and including the
Evans School of Public Affairs, the Department of Urban Design and Planning,
and Kittleson Associates.
Why is the Eastside Transportation Concurrency Study
The cities of Bellevue, Kirkland, Redmond, and Issaquah identified
four problems associated with current transportation concurrency practices
that this study will try to resolve:
Existing concurrency measures work against the Growth Management
Act. The objective of the GMA was to encourage land development
in compact centers where public services could be provided efficiently.
From a development perspective, concurrency may be discouraging
development in centers when traffic approaches level of service
(LOS) standards. Instead, development may move out to the urban
fringe to avoid concurrency related impact fees and permitting uncertainties.
This effect is contrary to the intent of the GMA, exacerbating sprawl
and contributing to even greater levels of congestion.
Cities must deal with vehicle trips that are diverted from congested
state freeways onto city streets. People making trips that should
be carried by the region's freeways are increasingly shifting to
city streets to find shorter travel times. This consumes capacity
that would otherwise be available to serve local land use.
There is little cross-jurisdictional coordination on LOS standards
or how to account for cross-jurisdiction trips. Travel is not restricted
to jurisdictional boundaries, so travel generated by land uses in
one city often affects streets in another. Given the way that cities
currently practice concurrency, they lack any collective means to
design solutions on a regional or subregional basis.
The methodology for determining LOS used by most local governments
accounts for only vehicle traffic during the busiest part of the
day compared with street capacity. This method does not reflect
person movement or provide for pedestrian, bicycle, or transit mobility
(except to the extent that they reduce vehicle trips). Existing
concurrency measures do not encourage the evolution of the multi-modal
transportation system needed to support the region's center-based
What are the goals of the Eastside Transportation
The cities of Bellevue, Redmond, Kirkland and Issaquah will work cooperatively
to accomplish the following:
- Assess different ways that the four cities measure concurrency,
evaluate the impact that current concurrency systems have had on supporting
the implementation of Vision 2020 and the Growth Management Act, and
identify opportunities and challenges associated with developing a
more uniform and coordinated system.
- Identify areas of common agreement on the use of concurrency regulations
and the principles involved in their application to determine whether
a mutually agreed set of outcomes among the cities is possible.
- Analyze alternative approaches for measuring concurrency (e.g.,
time of day, peak hour vs. peak period, delay, and methods that reward
or enhance multi-modal transportation solutions to broaden what is
now principally an auto-based accounting of traffic).
- Evaluate alternative approaches, focusing on helping Bellevue,
Kirkland, Redmond, and Issaquah comply with the intent of the Growth
Management Act and the region's Vision 2020 objectives, given the
current realities of congested freeways and regional trips.
- Develop specific recommendations for changes to state and local
laws to improve the effectiveness of concurrency methods over time.
Which cities are involved in the Eastside Transportation
What is the benefit of studying multiple cities?
Although each local city government is responsible for approving local
land use permits and determining a particular level of service standard,
decisions made in one city will affect neighboring cities. Therefore,
the Eastside Transportation Concurrency Study will investigate potential
concurrency changes to improve coordination on the sub-regional level,
as well as how state and regional transportation providers should be
Who is working on the Eastside
Transportation Concurrency Study?
The Executive Steering Committee (ESC) provides direction on key issues
and assists with shepherding the project through city councils and providing
guidance to the Technical Advisory Committee. The ESC comprises the
planning and public works directors of Bellevue, Redmond, Kirkland,
- Technical Advisory Committee
The Technical Advisory Committee (TAC) ensures that affected agencies
are involved and contribute their expertise in a timely and coordinated
manner. The TAC comprises staff from the cities of Bellevue, Redmond,
Kirkland, and Issaquah.
- University of Washington
The University of Washington Study Team will conduct the research,
develop written products, and present findings to the ESC, TAC, and
elected and appointed officials, as well as provide educational opportunities
for both the TAC and ESC. The Study Team comprises senior researchers
at the Washington State Transportation Center; the Evans School of
Public Affairs; the UW College of Architecture and Urban Planning;
and Kittelson and Associates.
How is the study being funded?
of Washington appropriated $250,000 of the motor vehicle account for the
Eastside Transportation Concurrency Study. In support of this effort,
the cities of Bellevue, Redmond, Kirkland and Issaquah are providing $100,000
in an in-kind staffing commitment match to the state grant.
When will the study be finished?
By November 1, 2003, a report of the findings will be made to
the transportation committees of the legislature.
Level of Service Standards
LOS stands for "level of service." It is a measure
of how well a given transportation facility is performing. In general,
LOS is reported as a grade ranging from "A" (very good) to "F"
Roadway LOS has been defined both mathematically and descriptively
by the Transportation Research Board (TRB) of the National Research Council
for a variety of roadway types. In simple terms, LOS A for any facility
means that traffic flows smoothly enough so that a driver's behavior (speed,
ability to change lanes) is not affected by other vehicles. LOS F means
that so many vehicles are on the facility that vehicle flow has broken
down and traffic moves inconsistently (i.e., stop and go traffic conditions).
LOS B through LOS E are evenly distributed between these extremes.
The mathematical calculations used to compute LOS vary from
one type of facility to another (e.g., the procedures for freeways are
different from those for intersections). However, because some of the
preferable measurements are hard to collect, simplified procedures that
compare the volume being carried with the theoretical capacity of the
facility are commonly used to estimate LOS for all types of roadway facilities.
LOS for transit systems, pedestrians, and bicyclists are less
well defined. TRB is currently developing, and at some point will adopt,
standard methods for computing LOS for these travel modes that can be
applied uniformly across the nation. Some jurisdictions already use measures
being considered as part of the TRB's development review process.
- How is capacity measured?
Roadway capacity is a function of the type of facility (arterial
versus freeway), its size (number of lanes), its lane configuration (e.g.,
any left turn lanes), and any control mechanisms (for example, the signal
timing used at an intersection). Formulas for computing capacity on roadways
are presented in the Highway Capacity Manual, as well as within several
other standard engineering texts. In some cases, authoritative texts provide
minor differences in capacity calculation. These differences, while minor,
allow engineers to trade the "precision" of capacity calculations
with the time and effort required to calculate such estimates. The simpler
versions of these equations ignore or don't estimate the minor effects
that some roadway design features have on measured capacity, which can
be captured more precisely with some of the more detailed (and resource
intensive) capacity calculation procedures.
Capacity is traditionally expressed as the maximum number of
vehicles that can use a facility in a one-hour period. This is important
for reviewing rush hour roadway performance. During rush hour, traffic
demand normally peaks. That is, volume demand is uneven throughout the
hour. Thus, even though the "hourly volume" is below "hourly
capacity," congestion may still occur during part of that hour. This
is because at the peak of the rush hour, volumes exceed what the roadway
can handle, whereas at other times during that same hour volumes are lower
than the roadway can handle.
- Why do cities measure capacity differently?
As noted above, the mathematics for computing roadway LOS vary
by facility type. As a practical matter, cities have neither the time
nor resources to measure capacity and LOS for all roadway attributes.
(For example, LOS can be computed for an entire arterial, as well as for
each intersection along that arterial, as well as for each approach to
each of those intersections.)
To limit the cost of LOS measurements, cities generally choose
to examine a subset of facility attributes when reviewing roadway performance.
They commonly attempt to choose the attributes that the city staff believes
most accurately reflect how the public perceives roadway performance.