Accessing Traffic Counter Data

Scroll Down for Information on how to access the Raw and Aggregated Traffic Counter Data collected on Ireland's National Road Network.

All data sets here are lincensed under the Creative Commons Attribution 4.0 International (CC BY 4.0) licence unless otherwise indicated. Details about how TII shares data with the Public can be found here .


This page provides some guidance on how to access the Traffic Counter Data hosted here. This data is shared publicly by Transport Infrastructure Ireland, in support of Ireland's Open Data Strategy.

This data set is a valuable source of information on vehicle movements across the national road network and is made available here in its raw form, in order to provide researchers, public bodies, engineering companies, as well as the general public, with the opportunity to analyse and query the data independently for their own specific purposes.

Downloading The Data

The data set provided here includes data from all available traffic counters. Please note that the traffic monitoring equipment consists of mechanical devices and, as such, is subject to failure. Therefore, there may be gaps in the data for short periods of time for specific counters while a unit is being replaced, upgraded or repaired. Similarly, over time, some devices are retired completely and are replaced with new devices. In such cases, data will cease from a given device identifier and will begin streaming from the replacement device with a new device identifier.

streaming from the replacement device with a new device identifier. The data is provided in files formatted as Comma Separated Values, also known as CSVs. It is published daily and each publication includes three files:

  1. 1. The largest file contains a complete set of all Per-Vehicle Records (PVRs) captured on that day.
  2. 2. A file containing the aggregation of PVRs by Vehicle Class (e.g. cars, busses, trucks) is also published. This is a significantly smaller file.
  3. 3. The last file is an aggregation of the vehicle count for each minute of the day by counter and is typically used to identify gaps in the data due to device failure etc.

Each file can be downloaded over the Internet using the standard HTTP protocol. This means a standard web browser is capable of downloading the files. The URL or link to each file has the same pattern for each of the three daily files described above and are written respectively as follows:

  1. https://data.tii.ie/Datasets/TrafficCountData/yyyy/MM/dd/per-vehicle-records-yyyy-MM-dd.csv
  2. https://data.tii.ie/Datasets/TrafficCountData/yyyy/MM/dd/per-site-class-aggr-yyyy-MM-dd.csv
  3. https://data.tii.ie/Datasets/TrafficCountData/yyyy/MM/dd/per-site-minutes-aggr-yyyy-MM-dd.csv
In each case above yyyy should be replaced with the four digit year of the date for which the consumer wishes to download data. Similarly, MM should be replaced with the two digit month and dd with the two digit day.

For example, to download data for 1 June 2013, the first day for which we have data, the respective URLs would be:

  1. https://data.tii.ie/Datasets/TrafficCountData/2013/06/01/per-vehicle-records-2013-06-01.csv
  2. https://data.tii.ie/Datasets/TrafficCountData/2013/06/01/per-site-class-aggr-2013-06-01.csv
  3. https://data.tii.ie/Datasets/TrafficCountData/2013/06/01/per-site-minutes-aggr-2013-06-01.csv

The first row of each file contains headers which describe each field. However, the meaning of some of these may not be apparent to consumers. The following explains some of the less obvious column headers:

The unique identifier for the traffic counter device. In conjunction with the site’s dataset, this can be used to determine the location and route of the counter, used to record the vehicle movement.
The Id of the lane in which the movement was recorded, which is specific to each counter.
If a value is present, this indicates that the vehicle may have been changing lanes as it passed over the counter.
This indicates the category of vehicle that was recorded e.g. car, bus, etc.
The approximate length of the vehicle recorded.
The approximate distance between the front of the recorded vehicle and the vehicle behind.
The approximate distance between the rear of the vehicle and the front of the vehicle behind.
This is available on WIM sites only and indicates the approximate weight of the vehicle.
If available, this indicates the approximate surface temperature of the road at the location of the device.
This is available on WIM sites only and indicates the number of axles detected for the vehicle.
This is available on WIM sites only and expresses as an array of real numbers, the weight over each axel in order.
This is available on WIM sites only and expresses as an array of real numbers, the distance between each of the axles.