Traffic Monitoring System

The Traffic Monitoring System (TMS) Team administers the Maryland Department of Transportation State Highway Administration (MDOT SHA) Traffic Monitoring Program. The program collects, processes, analyzes, summarizes, and disseminates Maryland highway traffic data. It is supported by a comprehensive, user friendly, management information computer database system.

Traffic Monitoring System Program

This document describes our program, including the sources, methodologies and procedures used to collect, calculate, and validate Annual Average Daily Traffic (AADT) counts. It includes the resulting traffic data reports, such as the Traffic Trends Report, Traffic Volume Maps, and Truck Volume Maps.

Traffic Data Collecting Information

The most recent roadside safety procedures and guidelines required by MDOT SHA for counting traffic. It includes templates that consultants can use for traffic counting data.

Email Me Service

Traffic Monitoring System has launched a new email service called Email Me. Requestors can email with either a location ID, road, corridor or county in the subject line. The service emails back the traffic data for the requested locations. You have an option of appending xls or excel to the subject to get the data in Excel rather than the pdf format.

AADT Locator

Enter a full or partial street address to find AADT's for that address by way of the Address Search option. The tool displays AADT & AAWDT (Annual Average Weekday Traffic) for locations within a search distance of that address.

An alternate way to find an AADT is by using the Route Search option wherein the user selects the County, Road Name / Route Number. The AADT locations are plotted in Google Maps and the list is displayed in a results window. The search panels, maps and results are all components of the same window.

Internet Traffic Monitoring System (I-TMS)

The I-TMS provides access to detailed traffic count data. Similar to AADT Locator, I-TMS also has Address Search and Route Search options wherein the user can filter for required locations. The tool displays locations in the results tab. You can select an individual location to view reports by class, volume, and other categories.

Traffic Volume Maps

This is a graphical representation of AADT numbers displayed at each location on Maryland's road network. Traffic counts are reported as the number of vehicles expected to pass a given location on an average day of the year for all traffic-counting stations in the State.

Truck Volume Maps

Truck Volume Maps are graphical representations that depict the average percentages of trucks at various locations on Maryland s roadways by county. Also included at these locations is the current AADT.

GIS Traffic Count Data

Traffic data, including AADT, AAWDT and Truck Percentages is available for download from our website as shapefile and Keyhole Markup Language (KML) files in NAD 83 Feet HARN.

Traffic Station History PDF icon  4.52 MB, Excel Icon 3.33 MB

This tabular report shows AADT in Maryland for the last seven years (2014 through 2020). The report lists the county, route number, road name and location, as well as the beginning  and ending mile points of the section, or road represented, by the AADT. It also includes the description of the road segment.

AADT, AAWDT & Truck Percentages PDF icon 4.21 MB , Excel Icon 3.33 MB

This tabular report shows AADT, AAWDT and Truck Percentages for 2020 in Maryland. The report lists the county, route number, road name, location, begin mile point, end mile point of the section or road represented by the AADT and a description of the road segment.

Vehicle Classification by Functional Class PDF icon 481 KB, Excel Icon 120 KB

This report shows the percentage of vehicle classifications by functional class for the years 1998 through 2020.

Factors to convert Volume to AADT

These reports have Group and Individual location factors to convert volume into Annual Daily Traffic for a given year.

2017 Excel Icon 899 KB (2017 Group Factors to convert volume to AADT.xlsx)
2018 Excel Icon 916 KB (2018 Group Factors to convert volume to AADT.xlsx)
2019 Excel Icon 168 KB (2019 Group Factors to convert volume to AADT.xlsx)
2020 Excel Icon 175 KB (2020 Group Factors to convert volume to AADT.xlsx)

If you have questions or concerns contact us at:

Maryland State Highway Administration
Traffic Monitoring System Team
707 North Calvert Street - MS C-607
Baltimore, Maryland 21202
Phone: (410) 545-5523


Traffic count data reports and data sets are provided as a public service by the Maryland Department of Transportation State Highway Administration (MDOT SHA).

Restriction of Liability

MDOT SHA makes no claims, promises or guarantees about the accuracy, completeness, or adequacy of the contents of these documents, and expressly disclaims liability for any errors and omissions in the contents of these documents. All route, traffic, and travel data being made available by MDOT SHA are developed to support internal uses, primarily transportation planning. Any and all data are provided "as is" with the understanding that no warranty of any kind, implied, expressed or statutory, is given with respect to the contents of this document. Any and all conclusions or products derived from the data are the sole responsibility of the user.


Information presented in this document is considered public information and may be distributed or copied.