Junction plan
Name every approach or arm and identify the movements to be reported.
Service 04
Turning movement count services for intersection data.
Movement-level traffic counts by approach, direction, interval and agreed road-user class, prepared through a defined observation and quality-review workflow.
How the study is observed
This original conceptual diagram illustrates the study structure. The exact methodology is confirmed against the approved project brief, available source material and local requirements.
Turning movement count authority
What is a turning movement count?
A turning movement count, often shortened to TMC, records how vehicles and other road users travel through an intersection during defined periods. Each observation is assigned to an approved approach and movement—such as left, through, right or U-turn—and can be reported by interval, vehicle class, lane or active-travel mode when the project requires it.
The count is designed around the engineering question and the actual junction layout. It provides observed movement data for traffic engineering, signal, access, capacity or operational work; it does not by itself calculate capacity or predict future demand.
Movement-level scope
From an intersection plan to a reviewable movement matrix.
The observation matrix is the control document for an intersection turning movement count. It keeps approach labels, movements, classes, crossings, intervals and exceptions consistent from the source footage through to the final deliverable.
| Road user | Movement definition | Possible output |
|---|---|---|
| Motor vehicles | Approach, left, through, right and approved U-turn paths | Agreed fixed intervals and vehicle classes |
| Pedestrians | Defined crossings and directions | Crossing totals or interval tables when scoped |
| Cyclists | Road, lane or crossing movement defined in the matrix | Separate or combined mode treatment as agreed |
TMC project inputs
Six decisions make the count specification clear.
Observation period
State the date, time zone, count windows and reporting interval.
Class dictionary
Define vehicle and active-travel classes before observation begins.
Footage coverage
Confirm each approach, lane and crossing needed by the matrix remains visible.
Output structure
Agree movement matrices, interval tables, peak summaries and client-template fields.
Exception rules
Record how occlusion, ambiguous paths and partial visibility will be treated.
Terminology across project teams
TMC, junction turning count and intersection movement count.
Project teams may use different labels for closely related movement-count requirements. In North American briefs, TMC and intersection turning movement count are common. UK and Irish briefs may use junction turning count, classified junction count or related MCC/JTC terminology. The agreed movement matrix and deliverable—not the label alone—define the service.
Deliverable confidence
Structured for review and engineering use.
Typical outputs can include approach-by-movement matrices, fixed-interval tables, vehicle-class splits, pedestrian or cyclist movements, peak summaries, source notes and recorded exceptions. Files are prepared in the agreed project or client structure, subject to what the source and approved scope support.
Traffic intelligence workflow
From movement observation to a usable project output.
Every study follows a defined path from the agreed scope to a reviewed, clearly presented deliverable. The visual below complements the service detail and is supported by the full HTML explanation on this page.
Study at a glance
Build an approach-by-movement matrix for left, through, right and U-turn paths at a defined junction.
Typical outputs
- ↳ Approach/movement matrices
- ↳ Classified interval splits where scoped
- ↳ Pedestrian and cycle movements where requested
Review focus
- ↳ Arm and lane labels
- ↳ Movement totals versus approach totals
- ↳ Blocked or ambiguous paths
What a TMC deliverable can contain
Movement, class and interval context.
A turning-movement output can retain the approved approach, movement, class and reporting-interval dimensions. The actual layout follows the site and study brief.
View synthetic sample deliverables →Approaches, arm count, lanes and movement rules are defined for the actual study; this diagram is a conceptual four-arm example only.
Service summary
Turning movement counts measure left, right and through movements by approach, time interval and, when scoped, vehicle or active-travel class.
When it is used
Use it for junction design, signal, access, capacity or operational decisions.
Methodology
Create an approach-by-movement matrix from the actual junction layout before the count.
Inputs and source requirements
Provide a junction plan, arm labels, periods, class scheme, crossings and output layout.
Movements and classifications
Each observed road user is assigned to the approved approach and movement path.
Time intervals
Usually report agreed fixed intervals so peak variation can be reviewed.
Typical deliverables
Movement matrices, interval tables, classified splits where required and method notes.
Quality control
Reconcile approach totals to movement totals and check each requested period and movement path.
Limitations
It records observed movements and does not alone calculate capacity or future traffic.
Privacy and security
Video sources and project files are handled only through approved transfer arrangements.
Frequently asked questions
Can a TMC include vehicle classes?
Yes. The class dictionary and movement matrix are agreed before observation.
Can signalised and unsignalised junctions be covered?
Yes, provided the layout and required movements are visible in the source.
Can a TMC include pedestrians and cyclists?
Yes. Crossings, directions and mode treatment should be included in the approved matrix.
What if an approach is partly hidden?
The affected movement or class follows the agreed exception treatment and the limitation is recorded.
- ISO 9001:2015Quality management
- ISO 27001:2022Information security
- Structured QA/QCDefined review checks
- Global supportProject-specific delivery