Steps to Creating a Travel Time System Using SmartSensor HD

Travel times provide drivers an estimate of how long it will take for them to get to their destination. An effective travel time system reduces congestion on

the road by helping drivers choose the best departure time and route for their journey; it also increases safety by creating more prepared, calm drivers. But

these travel times are only valuable to drivers if they are accurate, and the key to accurate travel times is SmartSensor HD. The following six steps will help

you understand how to use HD to create an effective travel time system.

2 Divide route into segmentsOnce you have a route, you can use

significant points along the road — such as DMS signs and popular on- and off-ramps — to help you divide the route into segments. A segment refers to any part of the route for which you have traffic data, like the speed, volume and occupancy data gathered by SmartSensor HD. The system will use the data from each segment to calculate travel times for all possible start and end points along your route.

1 Define a routeA route is the path a driver follows to

get from point A to point B. Choose a route that includes important destinations in the area like interchanges and airports.

6

WX-501-0157

How-To

SmartSensor HD provides point data — data taken from a certain spot on the route. Using current speeds from HD to calculate expected travel times will report changes in traffic congestion more quick-ly because speeds will start to slow for all sensors at or above the congested area almost immediately. Those lower speeds will start to influence the in-dividual segment travel times as soon as they are reported, which will influence the total travel time when the segments are added together. This gives operators a timely warning and an opportunity to report conditions to travelers ahead of time.

DID YOU KNOW?

How-To

4 Install and configure the sensorsWhen it comes time for the actual installation, try

to take advantage of existing poles and other infrastruc-ture whenever possible. If you need new poles, have them installed far enough away from the road that the sensor can have the requisite six-foot offset. At each mounting location, attach the sensor to the pole, then align it with the roadway so that is detecting all necessary lanes.

Configuring the SmartSensor HD to the roadway is quick and easy: simply connect to the SmartSensor HD software and run the auto-configuration tool. Your sensor will then be collecting data.

5 Get the data to the TOCThe data from SmartSensor HD can then be col-

lected by Collector — a web-based software system in the Wavetronix Command line. Collector can automatically gather the data then send it to Command’s Translator, where the magic happens.

6 Calculate and display travel timesThe Command Translator web interface allows

you to manage all of your route information, including the location of each sensor and travel point, and the data provided by SmartSensor HD. It uses all of this to create an XML file with accurate, forward-looking travel times, and this XML file can then be imported into a DMS control system or a public website, keeping drivers informed and happy. •

3 Choose mounting locationsOnce you have figured out your routes and seg-

ments, it’s time to figure out how many sensors you need along your route. This number will depend on your spe-cific road and budget, but a good rule of thumb is one sensor every half-mile to mile. For more urban areas you will want sensors more frequently — say, every quarter mile — and for rural areas you can space them out by as much as several miles. Just keep in mind that the bigger the gaps you have, the less accurate the trip time system will be.

How-To