canonical: https://jentic.com/apis/highwaysengland.co.uk/highwaysengland

# Highwaysengland WebTRIS Traffic Flow API

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.

## For AI 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.

## Scope

Does not handle real-time routing, incident reporting, or local authority roads - use for England strategic road network sensor reports only.

## Capabilities

- 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

### 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.

Example prompt: 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.

Example prompt: 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.

Example prompt: 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.

Example prompt: 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

| 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 |

## Key resources

- **Areas** — Regional boundaries of England's strategic road network with associated sites.
- **Sites** — Individual roadside monitoring stations with metadata.
- **Site Types** — Sensor technology classifications such as MIDAS and TAME.
- **Quality** — Daily and overall data quality metrics for sensor reliability.
- **Reports** — Daily and date-range traffic flow reports per site type.

## Why Jentic

- **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 handling:** 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.
- **Discovery method:** 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

- **Transport for London API** — London-specific transport data covering road, rail, and bus alongside the national WebTRIS feed.
- **TomTom Maps API** — Commercial real-time traffic and routing data, broader coverage than WebTRIS but paid.
- **HERE Maps API** — Global mapping and traffic platform with congestion and incident feeds.

## FAQ

### 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.