Eppley Airfield Parking Structure Expansion: Convenient and Economical
By Scott R. Froemming
Eppley Airfield is the commercial airline transportation center for the Greater Omaha (NE) / Council Bluffs (IA) and eastern Nebraska trade area, comprising approximately 1.2 million people. With a service area that extends into six states, Eppley ranks 65th in the nation’s airport rankings and is classified as a Medium Hub Commercial Service Airport by the Federal Aviation Administration (FAA).
Since the 1990s, Omaha has experienced periods of dramatic growth due to a surge in the area’s agricultural industry. Trade and economic growth have positively affected its business climate, leading to an increase in travel to and from the city. Originating enplanements grew from 1.81 million in 2002 to 2.21 million in 2007.
Recent projections by airport consultant Coffman Associates Inc. envisioned enplanement growth eclipsing 3.3 million in the intermediate term, and continuing up to 4.5 million enplanements in its long-term planning forecasts.
As Eppley Airfield’s operations increased, the Omaha Airport Authority developed an active “just do it” management philosophy.
As pre-recession growth rates showed that year-over-year enplanements grew roughly 4.5% through 2007 and Eppley’s public parking capacity was 7,209 stalls with a maximum observed daytime occupancy of 85%, the airport authority knew it had a need for additional parking.
For a better understanding of Eppley Airfield’s overall parking needs, as well as the opportunities afforded to the airport by the area’s economic growth, consultants analyzed the relationship between parking demand and enplanement statistics to ensure that customers were receiving optimal service. For coordinated planning, the parking and the airside terminal study were conducted simultaneously.
By reviewing current parking/rental car data and the operating conditions of the airport parking system, key parking parameters were identified to benchmark: parking revenue per parker, parking revenue per enplanement, and parking demand ratio per 1,000 enplanements. Rental car facilities housed within a parking structure contribute approximately 25% to total parking revenue.
Recognizing that a parking structure expansion would have to allow for consolidation and expansion of current terminal facilities without duplication, several parking structure options were studied, including multiple plan locations, building heights, construction phasing, building materials, amenities, code implications, cost estimates and schedules.
Once all of the data had been accumulated, the airport authority’s review of the findings confirmed project directives. A plan of action to pursue a parking structure addition moved from a planning concept to a credible business proposal and was submitted for review by the authority’s Board of Directors.
Twelve expansion concepts were presented for airport staff consideration with the following evaluation criteria:
• Impact on roadway traffic flow (long range)
• Impact on airport landside operations
• Project aesthetics
• Convenience – vehicle flow to / from new parking
• Convenience – pedestrian flow to / from new parking
• Disruption to parking / rental car operations
• Parking cost / added parking space
Parking Structure Expansion
The final approved expansion concept provided the largest parking area build-out possible within the existing site parameters. As the airport authority did not want the parking expansion to include remote facilities, two horizontal cast-in-place post-tensioned concrete additions, each six stories in height, served to increase parking space. Existing pedestrian vertical circulation elements and two pedestrian bridges from level three to the terminal remained in place.
Construction forced the closing of the previous entry points for all patrons using long-term garage and short-term parking. Temporary entry locations, using newly purchased entry equipment, provided patron ingress from Terminal Drive. The parking structure continued to operate during all phases of the construction.
Contract documents were prepared to define construction activity phases, limits and schedules. Construction fencing and plastic enclosures were designed to ensure safe and effective construction activity and public way separation. The construction contract included liquidated damages that coordinated with the project phases.
Eppley Airfield’s garage expansion features incremental parking system improvements; relocation of the entry parking equipment out of public view and into a well-lighted, secure, covered location; and improved vertical vehicular circulation through the modification of the long-term parker flow directly onto a one-way express ramp. In an effort to enhance public safety, the short-term entry drive also was relocated to a spot next to a pedestrian pathway leading to the terminal.
Cost and Features
The structure additions, totaling approximately 250,000 square feet, were completed for a construction cost of $9.5 million, or $13,176 per parking stall, and were in line with the original cost estimate. The General Contractor was Graham Construction of Omaha.
Construction features worth noting include:
• Deep pile foundations: 70’ - 90’ tipped steel pipe.
• New construction cantilevered 14’ toward existing structure.
• CIP post-tensioned construction.
• 6” slabs with 24’x60’ structural grid.
• Façade constructed of unitized concrete-filled steel pans.
The construction effort was completed in 14 months and allowed for continuous parking operations, with no more than 150 stalls displaced at any given time. The 721-stall parking expansion accommodated the airside consultants’ post-9/11 re-evaluation of expansion alternatives.
Overall, the Omaha Airport Authority’s desire to provide additional convenient parking for patrons, to improve upon the parking system performance, and to respect the long-term landside expansion opportunities, was successfully achieved.
Scott R. Froemming, P.E., Director of Operations in the Minneapolis office of Walker Parking Consultants, can be reached at email@example.com
Article Abstract from April, 2010