Minnesota Department of Transportation

511 Travel Info

State Aid for Local Transportation

E-Scene February 2022

Changes coming for traffic counting

By: Kim DeLaRosa, Needs Section Supervisor

MnDOT has permission from FHWA to use probe/mobile/StreetLight sourced Annual Average Daily Traffic (AADT) in a limited capacity for 2021. Although limited, 20,000 AADT or greater, local agencies will be asked for permission to use their location data that meet the criteria for official AADT.

There would be no cost to the locals as MnDOT already has a contract with and access to this mobile sourced AADT data. In general, only MnDOT staff, some of the larger local agencies, and select contractors working for MnDOT have access to the mobile data platform. The Traffic Data & Analysis (TDA) team would be pulling the mobile sourced AADTs for the entire state each year based on the AADT threshold that is deemed statically accurate for that year. It will not be done city by city, or county by county. For instance, the 2021 threshold is for count locations that have a past AADT of 20,000 or higher (there is about 1100 of these across the state).  In 2022 we hope it will drop to 10,000 AADT. Each mobile sourced AADT requires a spatial gate or box to be built in order to extract data from the vendors platform.  The TDA team will do this work to ensure the correct data at the correct location is pulled.  Each mobile sourced AADT value is still reviewed for percent change tolerances before it is used as a Draft AADT. 

The four year count cycle for cities and counties is on the carryover coding that started in 2020 and goes until 2023.  If cities or counties skipped counting, or did not complete counting, in those years they can count in 2022, 2023, or both.  The TDA website has details on the schedule, plus a reference to the past hardcoded count year before moving to the carryover cycle.