This page delivers traffic analytics for St. Mary's County, Maryland. Our metrics are calculated with multi-sourced, cross-verified data from real-world mobile and sensor networks, and averaged for St. Mary's County, Maryland among 332 road miles divided in 8,209 segments. Our metrics go beyond simple volume counts to provide actionable insights on traffic intensity, congestion, commercial vehicle flow, and network performance with highest possible granularity (average segment length is 213 ft). Whether you are evaluating a new retail location, planning logistics routes, or assessing infrastructure needs, this data helps you move from assumptions to certainty.
Data sourced from TrafficZoom's proprietary analytics platform.
The average number of vehicles that travel each day over any road in the road network.
6,003
Trucks
Trucks
The percentage of the total traffic volume composed of heavy vehicles.
5.3%
Average travel time
Average travel time
The average time of travel averaged among all vehicles traveling on the road network.
30.5 min
Congestion ratio
Congestion ratio
The rate at which the actual travel time exceeds free-flow travel time, averaged among all roads in the network.
16.3%
Drivers’ average age
Drivers’ average age
Average age of residents in the geographic areas where the vehicle trips originated.
45.1 yrs
Drivers’ average income
Drivers’ average income
Average income of residents in the geographic areas where the vehicle trips originated.
$122,833
Our data indicates an estimated average traffic volume of 6,003 vehicles per day in St. Mary's County, Maryland that results in 2,184,014 vehicle-miles traveled per day (≈797 million per year). The traffic stream is comprised of an average of 1 truck for every 19 vehicles. Typical time spent behind the wheel per trip is 30.5 minutes, which already accounts for delays at signals, intersections, and congestion.
Analytical insight
When compared to the Maryland state averages: St. Mary's sees 22% lower average daily traffic volume than the state average (6,003 vehicles per day against 7,693), suggesting less demand on each road - a critical factor for logistics and site planning. Across the whole network that adds up to 2,184,014 vehicle-miles traveled per day (≈797 million per year), roughly 1.6% of Maryland's statewide total. The average trip takes 30.5 minutes, 10% lower than the state level. The congestion ratio of 16.3% is 21% lower, pointing to smoother traffic flow than the state level - crucial for traffic control improvement and logistics planning. By volume, St. Mary's's 6,003 vehicles per day outpaces 65% of counties in Maryland. Its average travel time of 30.5 minutes is longer than 13% of counties in Maryland.
Highway vs. Non-Highway Traffic Analysis
Highway Traffic
Traffic
Traffic
The average number of vehicles that travel each day over any road in the road network.
17,851
Trucks
Trucks
The percentage of the total traffic volume composed of heavy vehicles.
5.6%
Average travel time
Average travel time
The average time of travel averaged among all vehicles traveling on the road network.
33.6 min
Congestion ratio
Congestion ratio
The rate at which the actual travel time exceeds free-flow travel time, averaged among all roads in the network.
39.0%
Drivers’ average age
Drivers’ average age
Average age of residents in the geographic areas where the vehicle trips originated.
45.5 yrs
Drivers’ average income
Drivers’ average income
Average income of residents in the geographic areas where the vehicle trips originated.
$122,294
A significant volume of traffic in St. Mary's County, Maryland utilizes the highway network. The average highway carries 17,851 vehicles per day, 259% more than the average non-highway road in the same area, which carries 4,974 vehicles per day. That average covers 55 highway road miles divided in 656 segments (average segment length 440 ft), together carrying 951,272 vehicle-miles traveled per day (≈347 million per year). Trucks constitute 5.6% of highway traffic.
Analytical insight
Highway truck concentration here runs 43% lower than the state average, at 5.6% - positioning St. Mary's as a primarily local traffic hub. For logistics operators, this validates the importance of local access. At 5.6%, St. Mary's's highway truck concentration is the lowest in Maryland. St. Mary's's highway truck count is higher than 9% of counties in Maryland, at roughly 998 trucks per day.
Non-highway traffic
Traffic
Traffic
The average number of vehicles that travel each day over any road in the road network.
4,974
Trucks
Trucks
The percentage of the total traffic volume composed of heavy vehicles.
5.0%
Average travel time
Average travel time
The average time of travel averaged among all vehicles traveling on the road network.
30.2 min
Congestion ratio
Congestion ratio
The rate at which the actual travel time exceeds free-flow travel time, averaged among all roads in the network.
14.3%
Drivers’ average age
Drivers’ average age
Average age of residents in the geographic areas where the vehicle trips originated.
44.6 yrs
Drivers’ average income
Drivers’ average income
Average income of residents in the geographic areas where the vehicle trips originated.
$123,253
The non-highway road network in St. Mary's County, Maryland supports a substantial volume of traffic. The average non-highway road carries 4,974 vehicles per day, 72% less than the average highway in the same area, which carries 17,851 vehicles per day. That average covers 277 non-highway road miles divided in 7,553 segments (average segment length 194 ft), together carrying 1,232,742 vehicle-miles traveled per day (≈450 million per year). Trucks constitute 5.0% of non-highway traffic.
Analytical insight
The concentration of trucks on non-highway roads is 10% lower than on highways. The non-highway congestion ratio of 14.3% is 25% lower than the state level, suggesting more efficient local mobility than the state average. Overall, average travel time here is longer than 13% of counties in Maryland. St. Mary's's average driver income exceeds 74% of counties in Maryland. St. Mary's's median driver age is higher than 15% of counties in Maryland.
Time-of-Day & Seasonal Patterns
Peak Traffic Windows
Weekday peaks:
AM peak 7:00 AM–8:00 AM and PM peak 12:00 PM–6:00 PM, with volumes reaching approximately 70% higher than the daily average.
Weekend traffic:
Weekend volumes run about 21% above weekday levels.
Seasonal Fluctuation
Busy season:
June–August is the high season, with volumes +33% versus the annual average.
Lowest month:
January is the quietest month, with volumes -25% versus the annual average.
Analytical insight
In St. Mary's County, Maryland, the peak hour concentrates about 7% of the day's traffic, and seasonal swing is pronounced at +33% in high season.
Traffic Flow Profile Comparison
Metric
St. Mary's
Maryland
Average
Difference
Traffic
6,003
7,693
-22.0%
Truck % (Total Traffic)
5.3%
7.5%
-29.4%
Truck % (Highway)
5.6%
9.8%
-42.7%
Avg. Travel Time
30.5 min
34.0 min
-10.4%
Frequently Asked Questions
The average daily traffic volume is calculated at 6,003 vehicles per day, providing a baseline for daily operations and site assessment.
Yes - St. Mary's has the lowest highway truck share of any county in Maryland, at 5.6%.
The average travel time for drivers is 30.5 minutes, offering a standard metric for commute and delivery route planning.
Approximately 18% of highway traffic and 4% of non-highway traffic consists of vehicles whose trip originates outside St. Mary's County, Maryland. This indicates that a portion of highway traffic is regional pass-through, while local roads are more representative of resident and commuter activity.
Weekday peaks occur between 7:00 AM and 8:00 AM in the morning and between 12:00 PM and 6:00 PM in the evening - about 70% above the daily average.
Trucks account for approximately 5.3% of the total traffic mix across all road types, with a significantly higher concentration of 5.6% on highways.
Traffic volumes are typically 33% higher during June–August. Volumes drop to their lowest levels in January, averaging 4,513 vehicles per day - a 25% decrease from the annual average.
Data Sources & Methodology
The data presented on this page is derived from TrafficZoom's proprietary analytics platform, which aggregates and normalizes information from multiple sources, including:
Mobile device location data (anonymized and aggregated)
