Data Feeds
Welcome to the CHART WEB Data Feeds. We provide data in two formats, JSON and XML.
The Traffic Incidents and Events data feed contains information for roadway events that may disrupt normal traffic flow. These events are tracked by our Traffic Operations centers statewide and updated as new information is made available.
| Field | Description |
|---|---|
| additionalData |
This object contains optional additional information for Traffic Events. It is a list of actionTypes.e.g. actionTypes [ { actionDescription: string, actionType: string }, ...] |
| closed | Boolean field indicating if the event is closed. |
| county | County where event occurred. |
| createTime | Timestamp. Date and time the incident was created. |
| description |
String formatted as event type @ location
e.g. Incident @ MD 42 NORTH NORTH OF GLADE RD where
event type is the string equivalent of the type field (click See field mapping below) and location is formatted as route @ Prior To/Past/landmark
|
| direction | Normal travel direction of the lanes affected by the incident. |
| id | Unique identifier assigned to each incident |
| incidentType |
Description of incident type. |
| lanes |
If lane data is available there will be one of these objects for each lane in the roadway where the event occurred. Click below for the fields and possible values. |
| lanesStatus |
A brief description of the lane status. i.e. Number of lane open, closed,... Empty if no lane data available for the event.
e.g. 1/4 Southbound-left Traffic Lane, left Shoulder, 4/4 Northbound-all 4 Traffic Lanes, Right Merge Lane, left Shoulder closed
|
| lastCachedDataUpdateTime | Last update time the event was cached. |
| lat | Latitude of the event location |
| lon | Longitude of event location |
| name | Name of the event. This is usually the same as the description. |
| other | Reserved for future use |
| opCenter | The Maryland State Highways operations center that reported the incident. |
| participants | SHA incident response unit ids. |
| participantOnScene | Boolean field indicating if responders are on scene. |
| source |
The entity type that reported the event to the Operations Center. |
| startDateTime | Timestamp. Date and time the incident was opened |
| trafficAlert | Boolean indicating if event was marked as a traffic alert. |
| trafficAlertTextMsg | If an incident is marked as a Traffic Alert this field contains an additional (optional) message to display to the user. |
| type |
Integer representing an event type. Items can be divided into 2 main categories: Incidents & Other Events. There are three types of incidents: Traffic Incidents, Weather Events and Road Closures. Any incident can be marked as a Traffic Alert. Traffic Alerts may contain an additional message to display to the user. |
| vehicles | The number of vehicles involved in the incident. |
The Road Closures data feed contains information for planned Construction, Maintenance and other temporary work zones that may disrupt normal traffic flow with daily temporary lane closures. Some long-term closures remain closed for extended periods of time. These events are tracked by our Traffic Operations centers statewide and updated as new information is made available.
| Field | Description |
|---|---|
| additionalData |
This object contains optional additional information for Traffic Events. It is a list of actionTypes.e.g. actionTypes [ { actionDescription: string, actionType: string }, ...] |
| closed | Boolean field indicating if the event is closed. |
| closureDays | Days of the week that lanes will be closed. |
| closureEndDate | Expected completion date of work. |
| closureEndTime | Time of day work is scheduled to cease. |
| closureStartDate | Date that work began or is expected to begin. |
| closureStartTime | Time of day that work is scheduled to begin. |
| county | County where closure is located |
| createTime | Date and time closure permit was created |
| description |
A brief description of the closure.
format Active Closure @ location At/Prior To/Past landmark
e.g. Active Closure @ MD 382 EAST/WEST PRIOR TO SASSCER LA
|
| direction | Normal travel direction of lanes closed. |
| id | Unique identifier for each closure event. |
| incidentType |
Description of incident type. |
| lanes |
List of lane objects - one for each lane where the closure is located. |
| lanesClosed |
A comma delimited list of lanes that are currently closed.
e.g. 1/1 Westbound-Traffic Lane, Shoulder, 1/1 Eastbound-Traffic Lane, Shoulder closed
Empty if no lane data available for the event. |
| lanesStatus |
A comma delimited list of lanes that are currently closed.
e.g. 1/1 Westbound-Traffic Lane, Shoulder, 1/1 Eastbound-Traffic Lane, Shoulder closed
Empty if no lane data available for the event. |
| lastCachedDataUpdateTime | Last update time the event was cached. |
| lat | Latitude of the closure location |
| lon | Longitude of the closure location |
| name |
Name assigned to closure event. Format is similar to description described above.
e.g. Active Closure @ MD 382 EAST/WEST PRIOR TO SASSCER LA
|
| opCenter | The Maryland State Highways operations center that reported the closure event. |
| other | Reserved for future use |
| participants | SHA incident response unit ids. |
| participantOnScene | Boolean field indicating if responders are on scene. |
| planned | This Boolean field that indicates whether the closure was a planned closure (true) or in response to other circumstances (false). |
| publicComments | Comments regarding the closure that SHA needs to share with the public. This field is often empty. |
| reason | The reason for work being performed. This field may be empty. |
| source |
The entity type that reported the event to the Operations Center. |
| startDateTime | Date and time that work is scheduled to begin. |
| trafficAlert | Boolean indicating if event was marked as a traffic alert. |
| trafficAlertTextMsg | If an incident is marked as a Traffic Alert this field contains an additional (optional) message to display to the user. |
| trackingNumber | An alternative unique identifier assigned to each closure. |
| type |
Integer representing an event type. Items can be divided into 2 main categories: Incidents & Other Events. There are three types of incidents: Traffic Incidents, Weather Events and Road Closures. Any incident can be marked as a Traffic Alert. Traffic Alerts may contain an additional message to display to the user. |
| vehicles | The number of vehicles involved in the incident. |
The Live Traffic Cameras data feed contains the traffic cameras on Maryland roads. Each camera has a road/route associated with it and may also be grouped into a regional category. The lat/lons are included with each camera along with the nearest milepost if applicable. It also provides the URL for the public to view the camera video.
| Field | Description |
|---|---|
| cameraCategories |
Defines regions across Maryland into which cameras may be grouped |
| commMode |
Camera communication mode |
| description | Human readable location of the camera. It consists of the route name or number followed by 1 or more nearby landmarks e.g. intersecting road, exit, ramp, mile marker |
| id | Identifier assigned to the camera |
| lastCachedDataUpdateTime | Last time cache was updated on the server |
| lat | Taken with latitude to locate the traffic camera on a map |
| lon | Taken with longitude to locate the traffic camera on a map |
| milePost | Nearest milepost to the camera. This field will be deprecated in a future release. |
| name | Name assigned to the camera |
| opStatus |
Operation status of the camera |
| publicVideoURL | Public access URL to view the camera video |
| routeNumber | The route number where the camera is located |
| routePrefix | The route type (US, MD, I) where the camera is located |
| routeSuffix | The route suffix where the camera is located. |
The Speed Sensor data feed contains the measured traffic speeds on Maryland roads where the Traffic Speed sensors are located. The direction and speed fields are being deprecated. Direction and speed data may be obtained from the zones field.
| Field | Description |
|---|---|
| commMode |
Speed Sensor communications mode |
| description |
Human readable location of the speed sensor. It consists of the route name or number followed by 1 or more nearby landmarks e.g. intersecting road, exit, ramp, mile marker |
| direction | This field is deprecated. Direction and speed may be obtained from the zones field. |
| id | Identifier assigned to the speed sensor |
| lastCachedDataUpdateTime | Last time cache was updated on server |
| lastUpdateTime | Last Time speed sensor data was updated |
| lat | Taken with latitude to locate the speed sensor on a map |
| lon | Taken with longitude latitude to locate the speed sensor on a map |
| name | Name assigned to the speed sensor |
| opStatus |
Speed Sensor operations status |
| owningOrg |
Organization owning the speed sensor |
| rangeOnly | Boolean indicating whether a speed range should be used to display the data or not |
| rotation | The rotation (or Bearing) for the TSS is the actual bearing. A bearing of 0 indicates due East and the bearing grows counter-clockwise, with 90 degrees indicating due North. The largest possible value is 359 which is one degree south of due East. |
| speed | This field is deprecated. Direction and speed may be obtained from the zones field. |
| zones |
Grouping of speed sensor objects from a single detector, usually by direction. Click below to see the zone object details |
The CHART System Weather Stations are comprised of Environmental Sensor Stations (ESS) in the field, a communication system for data transfer, and central systems to collect field data from numerous ESS. These stations measure atmospheric, pavement and/or water level conditions. Central Road Weather Information System (RWIS) hardware and software are used to process observations from ESS to develop nowcasts or forecasts, and display or disseminate road weather information in a format that can be easily interpreted by a manager. RWIS data are used by road operators and maintainers to support decision making.
The Roadway Weather Information System (RWIS) consists of full Weather stations reporting Atmospheric and Pavement conditions and Non-Invasive Roadway Sensors (NIRS) which utilize infra-red technology to detect pavement temperatures and roadway conditions.
For additional information on the Road Weather Information System (RWIS) hardware and software see the Frequently Asked Questions (FAQ) page of the Federal Highway Administration (FHA) Road Weather Management Program.
| Field | Description |
|---|---|
| airTemp | Air temperature in degrees Fahrenheit |
| description | The intersection location of the weather station |
| dewPoint | Dewpoint temperature in degrees Fahrenheit |
| fullRWIS | true for full Weather stations (RWIS) and false for Non-Invasive Roadway Sensors (NIRS) |
| gustSpeed | Wind gust speed in miles/hour |
| id | Unique identification number for each speed sensor weather station location |
| lastCachedDataUpdateTime | Last date and time weather station data was cached on the sever |
| lastUpdate | Date and time of the last weather station report |
| lat | Latitude in degrees of the weather station |
| lon | Longitude in degrees of the weather station |
| name | Name assigned to the speed sensor where the weather station is located |
| pavementTemp | High and low pavement temperature in degrees Farenheit |
| precipitationType | Type of precipitation detected by the weather station |
| relativeHumidity | Relative humidity percentage |
| visibility | Average visibility in miles |
| windDescription | Average wind direction and speed in miles per hour |
The Highway Message Signs data feed contains the message displayed on the dynamic message signs along with their location. The message is returned in three formats: HTML, NTCIP and plain text. The HTML (msgHtml) version is always available. The NTCIP version (msgMulti) is for messages that have multiple lines. The plain text version (msgPlain) is the NTCIP version with the markup removed so if msgMulti is empty, msgPlain will be empty as well.
| Field | Description |
|---|---|
| beaconsEnabled | Boolean field indicates whether or not the beacon is flashing (see hasBeacons field) |
| commMode |
Highway Message Sign communications mode. |
| description |
Human readable location of the message sign. It consists of the route name or number followed by 1 or more nearby landmarks e.g. intersecting road, exit, ramp, mile marker |
| hasBeacons | Boolean field indicates if highway message sign has a beacon |
| id | Identifier assigned to the highway message sign |
| lastCachedDataUpdateTime | Last time cache was updated on server |
| lat | Taken with latitude to locate the highway message sign on a map |
| lon | Taken with longitude to locate the highway message sign on a map |
| msgHTML | The message that is currently displayed on the highway message sign in HTML format |
| msgMulti | The message that is currently displayed on the highway message sign with NTCIP markup for multi-line text |
| msgPlain | The message that is currently displayed on the highway message sign in plain text (the msgMulti field without the markup) |
| name | Name assigned to the highway message sign |
| opStatus |
Highway Message Sign operations status. |
The Snow Emergency Plan data feed contains information on Snow Emergencies currently in effect and those that have been lifted within the last 24 hours.
| Field | Description |
|---|---|
| countyId |
Identifier (integer) for the county. Click on See field mappings below to see ID to county name mappings. |
| countyPolygons | This object contains the boundaries for the county effected by a snow emergency. |
| id | Unique identifier for the snow emergency |
| lastCachedDataUpdateTime | Last time when cached snow emergency data was updated on server |
| name | Name of the county affected by a snow emergency |
| snowEmergencyExceptionMsg | Snow Emergencies are declared on Maryland counties but some areas and/or roadways may be excluded. This text field describes the exceptions within the county. |
| timeDeclared | Date and time Snow Emergency was declared (EST or EDT as appropriate) |
| timeLifted | Date and time Snow Emergency was lifted (EST or EDT as appropriate) |
The Weather Related Road Conditions data feed contains road conditions reported during an event response. Road conditions are reported by maintenance shops and only apply within the shop's boundaries.
| Field | Description |
|---|---|
| county | County where the maintenance shop is located |
| description | Brief description returned as "Area-wide Condition at <maintenance shop> (Shop)" |
| id | Maintenance shop ID |
| interstate |
Interstate road conditions as reported by the maintenance shop. Interstate Road Conditions are returned as an object e.g. interstate: { description: string, group: int }Click below to see interstate road conditions object details. |
| lastCachedDataUpdateTime | Last time when cached weather road conditions data was updated on server |
| lastUpdate | Last time the road conditions were updated |
| lat | Latitude of the maintenance shop |
| lon | Longitude of the maintenance shop |
| name | Maintenance shop name |
| primary |
Primary road conditions as reported by the maintenance shop. Primary Road Conditions are returned as an object e.g. primary: { description: string, group: int }Click below to see primary road conditions object details. |
| secondary |
Secondary road conditions as reported by the maintenance shop. Secondary Road Conditions are returned as an object e.g. secondary: { description: string, group: int }Click below to see secondary road conditions object details. |
| shop | This field is deprecated. Use the id field instead |
| shopName | This field is deprecated. Use the name field instead |
Note: Equipment data shown below will be deprecated in a future release
| Field | Description |
|---|---|
| dumpTrucks | The number of dump trucks deployed |
| loaders | The number of front end loaders deployed |
| pickups | The number of pickup trucks deployed |
| snowBlowers | The number of snow blowers deployed |
| totalVehicles | The sum of the previous equipment types |