7 things you probably never knew about traffic counts

You know those black tubes that you see running across on the road? They usually make a “thump, thump” noise as you go over them? Well, that is us! Those tubes are used to count traffic and SRPC sets them all over the region every summer!

Here are 7 things you probably never knew about traffic counts:

1) The New Hampshire Department of Transportation assigns our data collection locations.

Every year, NHDOT assigns between 110 and 130 traffic counts to be collected within our region. NHDOT specifies the locations according to a 3-year rotating cycle and adds the data we collect to a statewide database that tracks such information as traffic patterns, traffic volumes, and types of vehicles. This information is available for annual traffic monitoring and can be used to aid local, state, or private projects.

This year, we collected data at 126 locations in 13 municipalities across the region. The northernmost count was by Province Lake in Wakefield, and the southernmost count was near Newmarket’s high school.

2) Cities and town can request their own traffic counts.

NHDOT is not the only organization that can request data collections! If you have a local project that you need information for or if you just want to monitor general traffic patterns, we can help!

The City of Rochester, for example, wanted to know how many cars and pedestrians travel each day through an intersection the city is reconfiguring. The site is not on the NHDOT’s revolving list, so we set up traffic counts and our new pedestrian radar counter to collect data the city can use to make design decisions.

The Town of Barrington requested traffic and pedestrian counts to determine how many people were using the town forest. We couldn’t use any of our equipment at the town forest parking lot, but after reaching out to a couple of our neighboring regional planning commissions we decided a game camera would be a good solution. In addition to recording cars and people, the camera captured some local domesticated furry canine friends—and a bear! Take a look!

3) They are not speed traps!

Although the equipment we use does have the capability to calculate speed, it cannot transmit the data to the police. So don’t worry, we aren’t trying to get you in trouble. When we do collect speed information, it is purely for planning purposes and to answer questions like “Are pedestrians safe when walking on the shoulder of this road? Should there be a median to separate the different lanes of traffic? Should the speed limit and road configuration be changed to better fit the flow of traffic?”

4) All the work we do is for you!

All the data we collect goes toward efforts to create a better road network for the residents of New Hampshire and visitors to the state. The numbers we report help NHDOT schedule priorities like paving and plowing and designate routes for emergency evacuations and freight transportation. The more information we have on past and present conditions, the better we can plan for the future.

5) You can tell what kind of data we are collecting by counting the number of tubes.

Each time a tire runs over of those black tubes, a pulse of air is sent to a little box on the side of the road. This device tracks the number of air pulses it receives and how close together it receives them. One tube indicates that we are solely counting how many cars use the road; this configuration is called a traffic volume count.

Two tubes are called a vehicle classification count. They tell us what types of vehicles are traveling on the road. By determining how long it takes one axle to go from one tube to the other, the counter tells us how many axles are traveling over the tubes and how far apart they are, which indicates the type of vehicle.

6) Setting traffic counts is a great way to get to know your local communities

We had many locations throughout the region where we got to set our equipment with a view. Our region is full of rivers, lakes, and parks. We would often stop at these places to take our lunch break and have a moment off the road and out of the summer heat. Take if from us, if you are ever feeling exhausted after a long day of pounding hardware into pavement, take 5 minutes to stick your feet in Province or Merrymeeting Lake. It makes a world of difference. On days when we didn’t pack lunches we got to try the sandwich shops of the region and found some awesome delis and lunch spots! We even stopped to buy local eggs when we saw roadside stands—some even sold goose and duck eggs! Setting traffic counts was a great way to get a closer look at some of the communities in our region and to see the local transportation networks that people travel everyday.

7) Working on the road is dangerous.

Twice this year accidents happened right in front of us. We were able to use our safety equipment to block off the scene and make sure it was safe before helping to direct traffic around the accident.

It wasn’t until we started doing traffic counts during the summer that we realized how vulnerable pedestrians are on the side of the road. We always display safety signs and wear fluorescent vests, but sometimes that’s not enough to grab the attention of those driving by. With all the road construction happening over the summer, it’s easy to become desensitized to roadside workers even when they are wearing brightly colored gear. As a result of a few close calls of our own, we periodically enlisted the local police to help keep us safe.

We primarily worked with the Rochester, Dover, and Lee police departments because their communities had some of the larger and more difficult intersections in our region. So next time you see us setting up equipment, please slow down and give us a wave!

To view the regularly monitored traffic locations around the state, please visit the NHDOT website.

For more information about the SRPC traffic count program or to request your own data collection, give our office a call at 603-994-3500 or send an email to Stefanie Casella.


This blog was co-authored by Monique Duchesne, data collection intern, and Stefanie Casella, data collection and analysis assistant.