Highwaysengland WebTRIS Traffic Flow API
Official vendor OpenAPI document · agent-readyIOTSensor Datanone10 EndpointsREST
For Agents
Query roadside traffic sensor data for England's strategic road network - list monitoring sites, fetch daily quality metrics, and pull traffic flow reports between dates.
Use for: I need to list traffic monitoring sites on the M25, I want to fetch yesterday's traffic flow for a specific site, Get the overall data quality for the strategic road network last month, Find all MIDAS sites in the South West region
Not supported: Does not handle real-time routing, incident reporting, or local authority roads - use for England strategic road network sensor reports only.
WebTRIS is the National Highways traffic data service for England, exposing roadside sensor data through ten REST endpoints. The API returns lists of monitoring sites, site types, regional areas, and daily and aggregated traffic quality metrics, plus site-level reports across configurable date ranges. It is unauthenticated and free to consume, which makes it suitable for transport analytics, journey planning research, and academic studies of motorway and trunk road traffic flow. Coverage is limited to the strategic road network operated by National Highways.
Install Jentic One Beta
Connect the WebTRIS Traffic Flow API to your agent
Jentic One is a self-hosted execution layer for AI agents. It lets your agent call the WebTRIS Traffic Flow API, or any other public or private API you need. You set the rules, the agent never sees your credentials, and every call is logged.
Two steps, two machines. Install the instance in a safe environment, then register your agent from wherever it runs.
1
Step 1: Jentic One Host machine
# On the machine that will host your Jentic One instance:
curl -fsSL "https://jentic.com/install.sh?src=apis&api=%2Fapis%2Fhighwaysengland.co.uk%2Fhighwaysengland" | sh2
Step 2: Agent machine
# On the machine where your agent runs (keep this separate from the instance):
curl -fsSL "https://jentic.com/install.sh?src=apis&api=%2Fapis%2Fhighwaysengland.co.uk%2Fhighwaysengland" | sh
jentic register # connects your agent to your Jentic One instanceJentic One is in public beta. The setup above keeps your agent separate from the instance, which is what you want before using real credentials: an agent running as the same OS user as Jentic One can read its stored keys directly. Just evaluating? A single local install is fine to start. See the secure deployment guide for the tiers.
Capabilities
What an agent can do with WebTRIS Traffic Flow API.
List all WebTRIS monitoring sites and retrieve a single site by ID
Enumerate site types such as MIDAS or TAME loops to filter monitoring stations
Pull regional area boundaries and the sites contained in each area
Fetch daily data quality scores per site to filter out unreliable readings
Retrieve overall data quality across the network for a given period
Run a daily traffic report for a specific site type
Run a date-range traffic report between a start and end date for any report type
Use Cases
Patterns agents use WebTRIS Traffic Flow API for, with concrete tasks.
★ Transport Analytics Research
Universities and consultancies studying motorway flow use WebTRIS to pull historic counts and speeds for England's strategic road network. The /reports/{start_date}/to/{end_date}/{report_type} endpoint returns aggregated metrics that can be loaded into a notebook without any authentication, so a research agent can build a dataset in minutes.
Pull the daily traffic report for site type 'MIDAS' between 2025-01-01 and 2025-12-31 and load the results into a pandas DataFrame.
Journey Time Quality Audit
Journey planning products that consume third-party congestion feeds need to verify that the underlying sensors were healthy. WebTRIS exposes /quality/daily and /quality/overall so an agent can score sensor reliability before treating downstream travel-time estimates as trustworthy.
For every site in area 7, fetch the daily quality score for the past 30 days and flag any site with quality below 80 percent.
Geographic Site Discovery
Engineering teams designing a new traffic study need a map of available monitoring sites. The /areas, /sites, and /sitetypes endpoints together describe the network: regional boundaries, sites within each area, and the technology installed at each site. An agent can enumerate this hierarchy without an API key.
List all areas, then for area 6 list all sites, and for each site report its site type from /sitetypes/{siteType_Id}/sites.
AI Agent Traffic Briefing
An AI assistant prepares a daily traffic briefing for a logistics operations team. Through Jentic, the agent searches for the relevant WebTRIS operation, loads the schema, and executes the GET against /reports for the chosen sites. No credentials are needed because WebTRIS is open, but Jentic still standardises the call surface alongside authenticated APIs.
Each weekday at 06:00, search Jentic for 'get daily traffic report from WebTRIS' and execute the report for the operations team's 12 monitored sites for the previous day.
Key Endpoints
10 endpoints — webtris is the national highways traffic data service for england, exposing roadside sensor data through ten rest endpoints.
METHOD
PATH
DESCRIPTION
GET
/v{version}/areas
List all regional areas
GET
/v{version}/sites
List all monitoring sites
GET
/v{version}/sites/{site_Ids}
Get details for selected sites
GET
/v{version}/quality/daily
Get daily site data quality
GET
/v{version}/reports/{report_type}
Get a daily traffic report
GET
/v{version}/reports/{start_date}/to/{end_date}/{report_type}
Get a traffic report between two dates
GET
/v{version}/areas
List all regional areas
GET
/v{version}/sites
List all monitoring sites
GET
/v{version}/sites/{site_Ids}
Get details for selected sites
GET
/v{version}/quality/daily
Get daily site data quality
GET
/v{version}/reports/{report_type}
Get a daily traffic report
GET
/v{version}/reports/{start_date}/to/{end_date}/{report_type}
Get a traffic report between two dates
Why Jentic?
What agents get from Jentic-routed access to this vendor.
Setup
Wiring the WebTRIS Traffic Flow API by hand means versioning each path segment yourself and assembling multi-part report URLs with site ids and date ranges, even though the service needs no credentials. Through Jentic you install once, import the WebTRIS Traffic Flow API from the API Directory, and your agent calls it through the same execution path as keyed APIs.
Permission scoping
WebTRIS is read-only over England's strategic road network, and its calls select sites and report windows through parameters rather than mutating anything, so scoping stays at the operation level: limit the agent to the operations it needs, such as listing sites or fetching a daily-quality report. You choose that set, so a broader report type is only available if you include it.
Credential isolation
WebTRIS is unauthenticated, so there is no credential to store, and Jentic still runs each call through the same execution path as keyed APIs. No secret ever enters the agent's prompt, logs, or context.
Intent-based discovery
Agents search Jentic by intent such as 'get a WebTRIS traffic report', and Jentic returns the matching sites or reports operation with its parameter schema so the agent picks the right endpoint without reading the reference docs.
Related APIs
Alternatives and complements available in the Jentic catalogue.
FAQs
Specific to using WebTRIS Traffic Flow API through Jentic.
What authentication does the WebTRIS Traffic Flow API use?
WebTRIS does not require authentication - there are no API keys or tokens. Through Jentic the API is wired into the same search and execute flow as authenticated APIs, so agents can call /sites and /reports the same way they call any other tool.
Can I pull historic traffic flow between two dates?
Yes. GET /v1/reports/{start_date}/to/{end_date}/{report_type} returns aggregated metrics across the requested window for the chosen report type. The matching daily endpoint /v1/reports/{report_type} returns a single day.
What are the rate limits for the WebTRIS API?
The OpenAPI specification does not declare rate limits. National Highways treats WebTRIS as a public service, so heavy batch jobs should add backoff and avoid parallel scraping of every site to remain a good citizen.
How do I find sites within a specific region through Jentic?
Run pip install jentic, then await client.search('list WebTRIS sites in an area'), load the schema for GET /v1/areas/{area_Ids}, and execute with the area ID. The response contains the sites for that area.
Does WebTRIS cover local council roads?
No. WebTRIS only covers England's strategic road network operated by National Highways - motorways and major A-roads. For local authority roads use the relevant council open-data portals.
How do I check whether sensor data is reliable for a given day?
Call GET /v1/quality/daily for the site and date in question. The quality score lets an agent decide whether to trust the underlying flow report or to fall back to a different site.
Can I limit what my agent is allowed to do with the WebTRIS Traffic Flow API?
Yes. Because you run Jentic One yourself, your own rules decide which WebTRIS operations the agent may call, and every WebTRIS endpoint is read-only, so scoping stays at the operation level. You can allow only the operations the agent needs, such as listing sites via GET /v1/sites or fetching a daily quality score via GET /v1/quality/daily, and leave out broader ones like the date-range report at GET /v1/reports/{start_date}/to/{end_date}/{report_type}. Since a report type or site is chosen through parameters rather than by mutating data, an operation you do not include is simply unavailable to the agent.
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