ACCESS Service Growth Management and Demand Estimation Model
Orange County Transportation Authority (OCTA), CA (2003 & 2005)

Orange County Transportation Authority Paratransit Growth Management:

In response to steadily increasing demand for Americans with Disabilities Act complementary paratransit services, the Orange County Transportation Authority (OCTA) desired a strategic response to manage Americans with Disabilities Act (ADA) trip growth.  AMMA Transit Planning led an internal working group to foster an integrated planning process, requiring each functional area of the agency to identify and take on responsibilities of managing ADA trip utilization.  Technical aspects of the study included extensive cost-analyses of the growth in demand and expenditures for ADA services.  There was heavy reliance upon the previously developed demand estimation model which detailed transit plans and impacts of strategies for slowing the otherwise predicted rates of trip growth.    
 
AMMA Transit Planning constructed a strategic process by which the Orange County Transportation Authority (OCTA) could contain and control the growth of Americans with Disabilities Act (ADA) complementary paratransit trips and budget levels, built from 19 strategic objectives with 64 specific, operational recommendations. These were aggressively implemented and documented impacts which were published by the Transportation Research Board, Transportation Research Record, December 2007, Vol. 2034.

                      

         

Orange County Transportation Authority ACCESS Demand Estimation Model:

To provide a basis for transit operational planning and in response to court decisions limiting trip denials for Americans with Disabilities Act (ADA) complementary paratransit trips, the Orange County Transportation Authority (OCTA) needed a statistically reliable method of projecting its ACCESS transportation demand.   Both passenger trips and vehicle hours’ demand projected over a three-year time horizon were needed. To identify reliable, valid variables for statistical projection, AMMA Transit Planning worked extensively with historical ADA passenger trip data and included over 1.8 million individual trip records.  These flat files were constructed from 3 ½ years of archived Trapeze data.  Other project elements included community outreach and literature search to identify potential predictor variables influencing demand. 

The 15 variable model developed used a multiple regression analysis to predict demand at confidence levels of over 99%, based upon historical patterns of trip use by type of day and time of year.   The demand model variables and its methodology adopted and in use by the agency was detailed in a government article published in the Transportation Research Board, Transportation Research Record, October 2004, Vol. 1984.

* AMMA was the prime contractor for both engagements, assisted by Transportation Planning and Policy [Costa Mesa, Ca.], Dan Boyle & Associates [San Diego, Ca.] and KFH Group, Inc. [Bethesda, Md.]