In combination, radio and OOH deliver a balance of sight and sound to an on-the-go audience
Radio adds frequency to the reach of an OOH message that the consumer might see only once (or once a day) on a billboard
Few radio listeners frequently change stations while in their cars, so a targeted message on radio can effectively supplement mass exposure to OOH creative.
Combining radio with an outdoor campaign will increase reach and recall:
Most OOH advertising is fixed and remains in place for a pre-set period of time. Radio ad copy can be changed quickly, so messaging changes can be implemented to supplement or clarify OOH
OOH ads can tweak consumer’s curiosity; radio ads will complement by delivering details
Inclement weather or adverse traffic conditions can adversely impact exposure to OOH advertising, but radio listening actually increases under these circumstances. American consumers depend on their car radios for weather and traffic reports, so OOH and radio make an effective drive-time combination every day.
For more information on radio:
Statistics and Trends: http://www.rab.com/whyradio/