By ROGER J. MASON and TIMOTHY A. BEVAN
CH2M Hill

Before I-405... before I-90... before I-5... Pacific Highway South, today's state Route 99, was the main highway connecting Seattle, Tacoma and Everett with points north and south -- reflecting the character of every community along its route.

Today the highway is an aging part of the region's transportation network, used as an alternative to freeways during peak traffic periods, carrying traffic past commercial strip developments from city to city.

Concerned about the lack of a clear community identity, the City of SeaTac chose to tackle state Route 99 by upgrading the 1.1-mile segment that runs parallel to Sea-Tac International Airport. Renamed "International Boulevard," the recently renovated stretch of highway has improved traffic and pedestrian circulation, increased safety, raised the quality of transit infrastructure, and upgraded the image of the community with aesthetic enhancements.

Retrofitting the corridor with amenities that improve community image, quality of life and economic redevelopment, required a non-traditional design approach. Because this is their main street, City of SeaTac officials wanted to do more than just widen the roadway to improve traffic.

Community leaders believed the character of their main street was fundamental to creating a new image and economic vitality for their city. And they all wanted a roadway that welcomed visitors and made residents feel secure enroute to their destination, whether that be Sea-Tac International Airport, a hotel or conference center, work, or just a leisurely walk.

Before the International Boulevard project began, the existing roadway had five-lanes (including a center two-way left-turn lane) with paved shoulders and few sidewalks.

There was undefined access to fronting properties. Traffic volumes ranged from 35,000 to 45,000 vehicles per day.

Five signalized intersections operated within the project limits, three of which provided inadequate service during peak traffic periods. Existing land uses along the boulevard included some of the region's largest hotels, a major access to the airport, airport-parking and rental car activity.

The City of SeaTac chose the consulting engineering firm CH2M Hill to help develop and implement this project. Non-traditional approaches were necessary to develop compromises between important technical and community issues. Continuous coordination with local leaders, businesses, citizens and agencies was critical to develop solutions for this project. The project incorporates traffic capacity enhancements, HOV/transit treatments, access management measures, pedestrian amenities and landscaping.

Construction of the first phase of the International Boulevard project was completed in August of 1996. Phase two, another one-mile segment to the south of phase one, is currently under construction and will be completed by the end of this year. The construction of phases three and four will follow to complete the SR 99 corridor within SeaTac's city limits.

Meanwhile, neighboring cities like Des Moines, and Federal Way have since initiated their own plans to redevelop SR 99. They also have retained CH2M Hill to help develop their own unique identity for the section of SR 99 through their town.

WSDOT's Office of Urban Mobility is just completing a comprehensive transportation planning study for a 14-mile segment of the SR 99 corridor from Tukwila to Federal Way to help guide those projects. This study will enable communities to implement their own unique look and feel to SR 99 while accommodating future traffic volumes and safety needs.

The International Boulevard project was the largest public works project ever undertaken by the new City of SeaTac.

The staff rose to the occasion and met the challenges associated with implementing a creative program to link community enhancements with improvements to the region's transportation system. The significant nature of the City of SeaTac's accomplishment the was recognized by the American Public Works Association (APWA) with the 1997 Washington State Transportation Project of the Year Award.

Roger J. Mason and Timothy A. Bevan are both engineers and transportation project managers with CH2M Hill.

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Copyright © 1997 Seattle Daily Journal of Commerce.