managing travel for planned special events - FHWA Operations ...

or variable message signs. CMSs are programmabletraffic control devices that canusually display any combination of charactersto present messages to motorists. Thesesigns are either: (1) permanently installedabove or on the side of the roadway, (2)portable devices attached to a trailer, or (3)portable devices mounted directly on a truckand driven to a desired location.Highway advisory radio is an effective toolfor providing timely traffic and travel conditioninformation to the public. It has variousadvantages and disadvantages. Its most importantadvantage is that it can reach moretravelers, or potential travelers, than theother roadside technology, changeable messagesigns. While CMSs reach only thosemotorists at a particular point, and can onlyconvey a short message, HAR has the advantageof being able to communicate withany person in the HAR broadcast range.Furthermore, the amount of information thatcan be conveyed to the user is much greater.Its primary disadvantage is that it is restrictedto low power, and this can lead topoor signal quality (since many outsideforces affect the signal, such as weather)and, therefore, poor listener levels.The public has learned to depend upon themedia to provide them with “almost” realtimetraffic information. Commercial radiohas proven to be a good means of providingtravelers with traffic information both in andout of their vehicles. It is not uncommon forplanned special event stakeholders, includingpublic agencies, to partner with a commercialradio station (or for a commercialradio station to sponsor a special event) toenhance the information dissemination relatedto the event and its transportation conditions.Care should be taken to ensure thatthe information disseminated reflects currenttraffic conditions and is credible.Other technology applications include:• Cellular telephone-based systems• 511• In-vehicle displays• Subscription services• Personal data assistantsAn en-route traveler information plan mustbe developed in concert with the traffic flowplan and traffic control plan. The success ofany traffic management plan depends ondisseminating correct information to motoristsat the right time and location.Detailed plans are necessary that identify thefacilities and resources to be used. For instance,what permanent CMS or HAR are tobe used and what holes exist in the informationdissemination strategy? Where willportable devices be required? Traveler informationplans must include planned messagesets for equipment and technology usedto disseminate en-route traveler information,including static signs, changeable messagesigns, highway advisory radio, and telephoneinformation systems.Traffic Surveillance PlanA traffic surveillance plan can include:• Closed-circuit television systems• Field observation• Aerial observation• Media reportsClosed-circuit television surveillance is avery valuable planned special event managementtool for observing real-time conditionsrelated to special event corridors, alternateroutes, parking and pedestrian conditions,as well as for a verification tool formessages placed on changeable messagesigns.3-42