TRB’s Transit Cooperative Research Program (TCRP) Report 121: Toolkit for Integrating Non-Dedicated Vehicles in Paratransit Service is a users manual for the Non-Dedicated Vehicle (NDV) Optimization Model that may be used to assist transportation managers in deciding the appropriate ratio between dedicated and non-dedicated paratransit service in a systematic and comprehensive manner. The NDV Model and test data are available online in a spreadsheet-based format. In addition to the toolkit, a Case Study Report and an Interim Report (which includes an analysis of factors that influence the mix of dedicated and non-dedicated paratransit service) are available for download.