Annual Vehicle Miles of Travel (AVMT) represents the estimated number of miles driven on Maryland's public highways for a given year. There are two components used to estimate AVMT - traffic count data and highway mileage. Traffic count data is summarized and reported as Annual Average Daily Traffic (AADT).

AADTs are calculated from short-term (48-hour) traffic counts performed on all publicly maintained roads in Maryland (including county and municipal). These counts are factored to account for seasonal variation in traffic patterns and represent an “Average Day”.

For planning purposes, AADT's are assigned to highway segments in order to provide a picture of traffic patterns is on the highway system on an average day. Highway mileage statistics are complied annually based on mileage reports from the local jurisdictions and SHA and MDTA offices. Any mileage changes are field verified by SHA's data collections crews.

AVMT is calculated by multiplying the AADT on a road segment by the segment length. Because AADT represents Daily traffic, the result is multiplied by 365 to represent Annual Vehicle Miles of Travel. (AVMT = AADT X SECTION LENGTH X365)

Maryland Bicycle Level of Traffic Stress (LTS) An overview of the methodology and attribute data is provided below. For a detailed full report of the methodology, please view the PDF published by the Maryland Department of Transportation here. The Maryland Department of Transportation is transitioning from using the Bicycle Level of Comfort (BLOC) to using the Level of Traffic Stress (LTS) for measuring the “bikeability” of the roadway network. This transition is in coordination with the implementation of MDOT SHA’s Context Driven Design Guidelines and other national and departmental initiatives. LTS is preferred over BLOC as LTS requires fewer variables to calculate including:Presence and type of bicycle facilitySpeed limitNumber of Through Lanes/Traffic VolumeTraditionally, the Level of Traffic Stress (LTS) (scale “1” to “4”) is a measure for assessing the quality of the roadway network for its comfort with various bicycle users. The lower the LTS score, the more inviting the bicycle facility is for more audiences.LTS Methodology (Overview) MDOT’s LTS methodology is based on the metrics established by the Mineta Transportation Institute (MTI) Report 11-19 “Low-Stress Bicycling and Network Connectivity (May 2012) - additional criteria refined by Dr. Peter G. Furth (June 2017) below and Montgomery County's Revised Level of Traffic Stress. Shared-use Path Data Development and Complimentary Road Separated Bike Routes DatasetA complimentary dataset – Road Separated Bike Routes, was completed prior to this roadway dataset. It has been provided to the public via (https://maryland.maps.arcgis.com/home/item.html?id=1e12f2996e76447aba89099f41b14359). This first dataset is an inventory of all shared-use paths open to public, two-way bicycle access which contribute to the bicycle transportation network. Shared-use paths and sidepaths were assigned an LTS score of “0” to indicate minimal interaction with motor vehicle traffic. Many paved loop trails entirely within parks, which had no connection to the adjacent roadway network, were not included but may be included in future iterations. Sidepaths, where a shared-use path runs parallel to an adjacent roadway, are included in this complimentary Road Separated Bike Routes Dataset. Sidepaths do not have as an inviting biking environment as shared-use paths with an independent alignment due to the proximity of motor vehicle traffic in addition to greater likelihood of intersections with more roadways and driveways. Future iterations of the LTS will assign an LTS score of “1” to sidepaths. On-street Bicycle Facility Data Development This second dataset includes all on-road bicycle facilities which have a designated roadway space for bicycle travel including bike lanes and protected bike lanes. Marked shared lanes in which bicycle and motor vehicle traffic share travel lanes were not included. Shared lanes, whether sharrows, bike boulevards or signed routes were inventoried but treated as mixed traffic for LTS analysis. The bicycle facilities included in the analysis include:

Standard Bike Lanes – A roadway lane designated for bicycle travel at least 5-feet-wide. Bike lanes may be located against the curb or between a parking lane and a motor vehicle travel lane. Buffered bike lanes without vertical separation from motor vehicle traffic are included in this category. Following AASHTO and MDOT SHA design standards, bike lanes are assumed to be at least 5-feet-wide even through some existing bike lanes are less than 5-feet-wide.
Protected Bike Lanes – lanes located within the street but are separated from motor vehicle travel lanes by a vertical buffer, whether by a row of parked cars, flex posts or concrete planters. Shoulders – Roadway shoulders are commonly used by bicycle traffic. As such, roadways with shoulders open to bicycle traffic were identified and rated for LTS in relation to adjacent traffic speeds and volumes as well as the shoulder width. Shoulders less than 5-feet-wide, the standard bike lane width, were excluded from analysis and these roadway segments were treated as mixed traffic.

The Office of Highway Development at MDOT SHA provided the on-street bicycle facility inventory data for state roadways. The shared-use path inventory and on-street bicycle facility inventory was compiled from local jurisdiction’s open-source download or shared form the GIS/IT departments. Before integrating into OMOC, these datasets were verified by conducting desktop surveys and site visits, and by consulting with local officials and residents.
Data UsesThe 2022 LTS data produced through this process can be used in a variety of planning exercises. The consistent metrics applied across the state will help inform bicycle mobility and accessibility decisions at state and local levels. Primarily, the LTS analysis illustrates how bikeable Maryland roads are where the greatest barriers lie. While most roads in the state are an LTS 1, the main roadways which link residential areas with community services are typically LTS 4. In the coming months, MDOT will use the LTS in variety of way including:

Conducting a bicycle network analysis to develop accessibility measures and potential performance metrics. Cross-referencing with state crash location data; Performing gap analysis to help inform project prioritization.

Data Limitations A principle of data governance MDOT strives to provide the best possible data products. While the initial LTS analysis of Maryland’s bicycle network has many uses, it should be used with a clear understanding of the current limitations the data presents.

Assumptions - As noted earlier in this document, some of the metrics used to determine LTS score were estimated. Speed limits for many local roadways were not included in the original data and were assigned based on the functional classification of the roadway. Speed limits are also based on the posted speed limit, not the prevailing operating vehicle speeds which can vary greatly. Such discrepancies between actual and assumed conditions could introduce margins of error in some cases. As data quality improves with future iterations, the LTS scoring accuracy will also improve. Generalizations - MDOT’s LTS methodology follows industry standards but needs to account for varying roadway conditions and data reliability from various sources. The LTS methodology aims to accurately capture Maryland’s bicycle conditions and infrastructure but must consider data maintenance requirements. To limit data maintenance generalizations were made in the methodology so that a score could be assigned. Specifically, factors such as intersections, intersection approaches and bike lane blockages are not included in this initial analysis. LTS scores may be adjusted in the future based on MDOT review, updated industry standards, and additional LTS metrics being included in OMOC such as parking and buffer widths.
Timestamped - As the LTS score is derived from a dynamic linear referencing system (LRS), any LTS analysis performed reflects the data available in OMOC. Each analysis must be considered ‘timestamped’ and becoming less reliable with age. As variables within OMOC change, whether through documented roadway construction, bikeway improvements or a speed limit reduction, LTS scores will also change. Fortunately, as this data is updated in the linear referencing system, the data becomes more reliable and LTS scores become more accurate. --------------------------------------------------------------------------------------------------------------------------------------------------------------------Level of Traffic Stress (LTS) Attribute Metadata OBJECTID | GIS Object IDState ID (ID) | Unique identification number provided by Maryland State Highway Administration (MDOT SHA)Route ID (ROUTEID) | Unique identification number for the roadway segment/record as determined by Maryland State Highway Administration (MDOT SHA) From Measure (FROMMEASURE) | The mileage along the roadway record that the specific roadway conditions change and maintain the same conditions until To MeasureTo Measure (TOMEASURE) | The mileage along the roadway record that the specific roadway conditions change and maintain the same conditions since From MeasureRoadway Functional Class (FUNCTIONAL_CLASS) | The functional classification of the roadway as determined by the Federal Highway Administration in coordination with the Maryland Department of Transportation State Highway Administration (MDOT SHA). All roadway records have a functional classification value. The following values represent the functional classification:

1 - Local 2 - Minor collector 3 - Major collector 4 - Minor arterial 5 - Principal Arterial (other) 6 - Principal Arterial (other Freeways and Expressways) 7 - Interstate

Annual Average Daily Traffic (AADT) | The Annual Average Daily Traffic (AADT) represents the average number of motor vehicles that pass along a roadway segment during a 24-hour period. The value is derived from MDOT SHA’s Traffic Monitoring System (TMS), the state’s clearinghouse for all traffic volume records. Roadway Speed Limit (SPEED_LIMIT) | The posted speed limit for a roadway segment as assigned by the MDOT SHA for state roadways and the local jurisdiction’s transportation management agency. Values for SPEED_LIMIT are measured in miles per hour (mph) in 5 mph increments from 5 mph through 70 mph. Roadway Access Control (ACCESS_CONTROL) | The access control indicates the types of entry points along the roadway segment, ranging from full to no access control. Interstates and other state roadways with no at-grade crossings are full access control, whereas a neighborhood street open to all modes of traffic represents a roadway with no access control. The values in