The StreetLight Advanced Traffic Counts API provides on-demand access to a wide range of traffic metrics. Each metric is calculated per road segment, based on the geometry you specify in your metrics query.

Metrics are returned as columns in the response for each segment you request via the fields parameter of the metrics call.

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Each row returned from the Metrics endpoint counts against your segment quota, even if segments are repeated. For more information, se Segment Quota Usage.

All Advanced Traffic Counts users can query the Base Metrics below. Users with Plus subscriptions can query the Plus Metrics below. If you would like to change your subscription, contact your StreetLight representative.

For metrics that are only available for specific data sources, these data sources are listed in the description of the metric. You specify the data source as a parameter in the request to the Metrics endpoint. Due to different sources and methodologies used to calculate metrics, we do not recommend comparing across data sources. For more information in the StreetLight Help Center, see What are data sources? .

Base Metrics

These core metrics are available to all Advanced Traffic Counts users.

Metric	Description
`mode`	Travel mode associated with the metrics.
`country_code`	Country of the geometry provided.
`segment_id` (required)	Unique ID for each segment.
`match_dir`	Direction of travel relative to the segment’s defined direction: - `1`: With direction - `2`: Against direction - `3`: Bi-directional
`year_month`	Year and month of the data.
`vmt`	Vehicle Miles Traveled (US only): volume × segment length.
`vkt`	Vehicle Kilometers Traveled (Canada only): volume × segment length.
`trips_volume`	Estimated vehicle volume, calculated using StreetLight ML models.
`trips_sample_count`	Number of sample trips on the segment during the data period.
`day_type`	Day classification: - `1–7`: Sunday to Saturday - `-1`: Weekday - `-2`: Weekend - `-3`: All days
`day_part`	Time of day: - `0–23`: Hour of day - `-1` to `-8`: 3-hour bins - `-10`: All day

Plus Metrics

Trip Attributes

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Speed values are in miles per hour for U.S. geographies and kilometers per hour for Canadian geographies.

Speed metrics

Metric	Description
`max_1_hr_speed`	Maximum average speed over a one-hour period in the month.
`avg_speed`	Mean speed across trips traversing the segment.
`speed`	Distribution in 5 mph speed bins.
`free_flow_speed`	95th percentile speed (hourly average across month). `agps` only.
`free_flow_factor`	Ratio of `avg_speed` to `free_flow_speed`. `agps` only.
`speed_percentiles`	5th to 95th percentile speeds in 5% increments (array of 19). `agps` only.
`speed_count`	Number of trips contributing to speed metrics. `agps` only.
`seg_travel_time_secs`	Time to traverse segment at `avg_speed`. `agps` only.

Distance to/from the segment

Metric	Description	Source
`start_distance`	Distance from segment to the start of each trip. Returns the following: Pedestrian queries: - `start_dist_lt025` (<¼ mi) - `start_dist_025_05` (¼–½ mi) - `start_dist_05_075` (½–¾ mi) - `start_dist_075_1` (¾–1 mi) - `start_dist_1_2` (1–2 mi) - `start_dist_gt2` (>2 mi) Vehicle queries: - `start_dist_lt05` (<½ mi) - `start_dist_05_1` (½–1 mi) - `start_dist_1_2` (1–2 mi) - `start_dist_2_5` (2–5 mi) - `start_dist_5_10` (5–10 mi) - `start_dist_10_25` (10–25 mi) - `start_dist_25_50` (25–50 mi) - `start_dist_50_100` (50–100 mi) - `start_dist_gt100` (>100 mi)	`lbs_plus`, `cvd_plus`
`end_distance`	Same ranges as `start_distance`, applied to trip end locations.	`lbs_plus`, `cvd_plus`
`home_distance`	Distance from segment to inferred home location. Same ranges as above.	`lbs_plus`
`work_distance`	Distance from segment to inferred work location. Same ranges as above.	`lbs_plus`

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For more information in the StreetLight Help Center, see Home and Work Location Methodology .

Traveler Attributes

Demographic characteristics of travelers. Only available for lbs_plus data source.

Metric	Values
`trip_purpose`	- `hbw`: Home-Based Work - `nhbw`: Not Home-Based Work (1 – `hbw`) - `hbo`: Home-Based Other - `wbo`: Work-Based Other
`income`	- `inc_lt_10k`: < $10,000 - `inc_40_45k`: $40,000–$45,000 - `inc_gt_200k`: > $200,000 (more brackets available)
`education`	- `edu_lt_9gr`: < 9th grade - `edu_9_12gr`: 9th–12th, no diploma - `edu_highschool`: High school graduate - `edu_some_college`: Some college/associate’s - `edu_associate`: Associate degree - `edu_bachelor`: Bachelor’s degree - `edu_graduate`: Graduate/professional degree
`race_ethnicity`	Race: - `white`, `black`, `indian`, `asian`, `islander`, `other_race`, `multiple_races` Ethnicity: - `hispaniclatino`, `nothispaniclatino`
`household`	- `hhkids_withkids`: With children - `hhkids_nokids`: Without children - `hhkids_lt6yr`: With children <6 years - `hhkids_6to17`: With children 6–17 yearsDemographic characteristics of travelers. Only available for lbs_plus data source.

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For more information in the StreetLight Help Center, see Traveler Attributes .

Vehicle Attributes

Describes vehicles in sample. Only available for cvd_plus data source.

Metric	Values
`body_class`	- `body_class_coupe` - `body_class_cuv` - `body_class_hatchback` - `body_class_minivan` - `body_class_motor_home` - `body_class_other` - `body_class_pickup` - `body_class_sedan` - `body_class_supermini` - `body_class_suv` - `body_class_truck`
`power_train`	- `power_train_ev`: Electric - `power_train_hv`: Hybrid - `power_train_ice`: Internal combustion - `power_train_other`: Other
`model_year`	- `model_lt_2016`: Before 2016 - `model_2016` through `model_2022`: Specific model years