Meeting the mobility needs of an aging population is a critical challenge facing California. The number of residents age 60 and above will grow to 13.9 million by 2050, representing over 25% of the state’s population, and the number of residents age 85 and above is expected to increase by over 70% between 2010 and 2030. Many older adults, who have been auto dependent, will reduce or stop driving for medical and non-medical reasons, substantially reducing mobility and activity. These limitations increase among low-income older adults and in neighborhoods where mobility options are limited. Transportation agencies are developing plans to expand mobility options beyond driving to address the needs of disabled and older adults. The Coordinated Public Transit–Human Services Transportation Plan (2018), adopted by the Metropolitan Transportation Commission (MTC), prioritizes cost efficient mobility options for seniors, people with disabilities, veterans, and people with low incomes. Contra Costa County (CCC) is implementing an Accessible Transportation Strategic (ATS) Plan, which supports a similar strategy. The problem and challenge with these plans are to provide information for appropriate and efficient implementation. The Contra Costa Transportation Authority (CCTA) is embarking on several major programs to enhance mobility for all residents, including older adults and disabled persons. Travel options and quality of life for older adults can be greatly enhanced if efforts are made to develop innovative mobility solutions beyond use of private vehicles, including (a), making transit improvements based on need, (b) encouraging rideshare services to accommodate those with disabilities, (c) offering resources for people at risk for missing important activities due to lack of transportation or mobility loss, (d) identifying and focusing on mobility challenged geographic areas and demographic groups, and (e) helping older adults to age in place. A previous study conducted by SafeTREC in 2017/18 on older adult mobility in CCC addressed these topics. The research team will work with the CCTA to use research findings from this previous work, in conjunction with a follow-up survey, to inform implementation of the ATS plan and other plans with similar goals. Major steps in the project are: (i) convene a work group of CCTA, MTC, and community stakeholders and others doing research and practice in this area that will provide input on the deliverables; (ii) synthesize the results of the CCC Older Adult Mobility Survey and ATS plan to help design the proposed follow-up survey (80% of 500 participants in the 2017-18 survey age 55+ agreed to follow-up); (iii)develop a toolkit that translates methods and findings from the 2017/18 project and the current 2019/20 project; and (iv) communicate findings to stakeholders.