Travel Time Information Systems

Travel Time Systems

What is a Travel Time System?

Travel Time Systems are ones which calculate the average driving time from a set geographical point A to point B on a roadway. Travel time information is displayed to drivers via portable or fixed electronic message boards. It's purpose to inform the driving public how long it will take to get to a set destination which allows them the possibility to detour around congested areas. Often detouring is not an option but many studies have shown that drivers appreciate knowing how long a drive will take irregardless of their ability to react to it. This information allows them to make arrangements for a delayed arrival as well as simple peace of mind that their trip will take a known set amount of time. Travel time systems are deployed in both permanent and temporary applications and a vital part of smart work zones where long unexpected delays are possible

How does a Travel Time System work?

Travel time systems work through the analysis of collected traffic data. This data can be collected via cellular providers, GPS vendors, mobile app vendors and most popularly through Bluetooth and Wifi Scanning. Bluetooth and Wifi scanning technology makes use of non-intrusive roadside sensors to detect the unique addresses of the Bluetooth and Wifi radios inside of drivers vehicle and smartphone. By picking up a unique radio ID at one sensor location and then another these systems are able to calculate the travel time experienced from sensor A to sensor B for that unique vehicle/driver. These systems collect and calculate thousands of data points like this in order determine the average travel time between any two sensors on the road.

Wait? What about Privacy?

Privacy is a huge concern for these types of systems. Because these systems track unique identifying numbers it is very important to ensure that these number are constantly scrambled and encrypted so that the data cannot be traced back to individual users/drivers. Most systems transform/scramble unique ID's immediately into altered numbers and then use those altered numbers for calculations throughout the day. Typically once per day the encryption algorithm used to scramble the numbers is changed to a new random value such that no day to day tracking/comparisons of unique ID's is possible.

How Effective is it?

Bluetooth and WiFi data is only captured from approximately 15% of the driving population. While this may seem like a low number it is more than enough data to calculate extremely accurate travel time. As smart phones and newer Bluetooth equipped vehicles become more prevalent this number will increase more and more.