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

Further benefits are realized. 511 puts a“face” on ITS and transportation operations,while increasing attention on the potentialfor traveler information services.With 511, transportation agencies can offereasier access to information via telephone,and have the same number work in multipleplaces. It is not uncommon for traveler informationnumbers to change across jurisdictionalboundaries, creating confusionamong motorists.In-Vehicle DisplaysA video display terminal (VDT) mounted inthe dashboard is another form for communicatingwith motorists in their vehicles. Thisis primarily a private sector industry, whichhas not been used widely for informationdistribution. These systems can be used toprovide motorists with route guidance andnavigational information in one of two differentformats. One approach is to presentthe driver navigation and route guidance informationin the form of maps or equivalentdisplays. With these systems, a global pictureof the traffic network can be provided.Recommended routes can be highlighted onthe video map display as well. In anotherapproach, simple symbolic signals (e.g., arrows,text instructions, or a combination ofboth) guide the driver along a recommendedroute. Some prototype systems use a varietyof displays depending upon whether or notthe vehicle is in motion, the functions selected,and level of informational and navigationaldisplays available.In-vehicle VDTs offer a number of advantagesover available technologies in providinginformation to motorists while driving.These include the following:• Travel information is more readily accessibleto the driver (providing continuousaccess to current position, routing,and navigational information).• Computer-generated navigational mapsand displays are logical extensions oftraditional forms of providing driverswith route guidance and navigation information.Information can be displayed in text, graphics,or both and tailored to the needs and desiresof each motorist. There are also limitationsto in-vehicle VDTs. These include thefollowing:• Drivers have to take their eyes off theroadway in order to receive the information.• In-vehicle VDTs present the driver withcomplex maps and diagrams that maycreate a potential to overload the driverwith too much information.• VDTs may also add to the visual clutteralready inside the vehicle.As technology continues to improve, theHead-Up Display (HUD) has become anotheralternative to in-vehicle VDTs for presentingvisual navigational and route guidanceinformation to motorists. Althoughoriginally developed for the aviation industry,several automobile manufacturers arebeginning to develop HUDs for presentingvehicle status and navigational informationto drivers.A wide variety of options for displaying informationmay be available using HUDs.Through both icons and alphanumeric text,navigation and route guidance informationmay be projected directly into the driver’sfield of view. This is expected to reduce theneed for visual scanning between two informationsources (the inside instrumentpanel and the outside environment) and theassociated visual accommodation time.6-68