Joe, Both of them need to be in a fx declarations block and the name spaces are wrong.xmlns:supportClasses="com.esri.ags.tasks.supportClasses.*"
xmlns:tasks="com.esri.ags.tasks.*"
<fx:Declarations>
<tasks:RouteTask id="routeTask"
concurrency="last"
fault="faultHandler(event)"
requestTimeout="30"
showBusyCursor="true"
solveComplete="solveCompleteHandler(event)"
url="http://tasks.arcgisonline.com/ArcGIS/rest/services/NetworkAnalysis/ESRI_Route_NA/NAServer/Route"
/>
<supportClasses:RouteParameters id="routeParams"
stops="{stops}"
returnDirections="true"
directionsLengthUnits="{directionlengthunits}"
impedanceAttribute = "Time"
preserveFirstStop = "true"
preserveLastStop = "false"
returnStops="true"
findBestSequence = "{Best_Sequence.selected}"
outSpatialReference="{map.spatialReference}"
barriers="{barriers}"/>
</fx:Declarations>