The future deployment of dedicated short range communication (DSRC) technology requires that DSRC-based applications are integrated with existing traffic management techniques so that non-DSRC-equipped vehicles at the early stage of DSRC deployment can also reap the potential benefits of DSRC technology. We have successfully developed and field demonstrated a hybrid traffic-information system combining DSRC technology and portable changeable message signs (PCMS) for work zone environment to improve traffic mobility, and thereby, driver safety. The developed system uses DSRC-based V2I and V2V communication to acquire travel safety parameters such as travel time (TT) and starting location of congestion (SLoC), and disseminate these parameters to both DSRC-equipped vehicles and DSRC-equipped PCMSs, which are strategically placed alongside the road. Using the DSRC-PCMS interface designed for this purpose, PCMSs can receive these travel safety parameters from nearby DSRC-equipped vehicles on the road via DSRC-based V2V communication, and display them for the drivers of the vehicles lacking DSRC capability. Such a system can be useful for an early stage of DSRC deployment when the DSRC market penetration is low. Additionally, a rigorous analysis has been conducted to investigate the minimum DSRC market penetration rate needed for successful functionality of the developed system with respect to both acquisition and dissemination of TT and SLoC. Using realistic traffic flow model, guidelines are developed to estimate a minimum DSRC penetration rate needed to deploy the developed system for a variety of traffic scenarios on a given work zone road.