Outputs
The model produces a single output product, described in the handbook as the projected impact on link-level speed.
It is a link-level dataset giving, for each Strategic Road Network link, two values.
The two values
| Value | What it is |
|---|---|
| Resilience coefficient | The link's estimated sensitivity of travel speed to rainfall |
| Projected travel speed | The link's speed under combined future demand and climate scenarios |
The resilience coefficient
This is the model's core quantity: how much speed this particular link loses as rainfall intensity rises.
A coefficient, not a verdict
The coefficient describes sensitivity, not importance. A highly sensitive minor link may matter less than a mildly sensitive strategic one carrying twenty times the traffic.
Reading it usefully means combining it with volume and with what the link connects, which is why the output is designed to be mapped rather than ranked.
The projected travel speed
The second value is the forward-looking one. It combines the coefficient with projected future demand and extreme climate rainfall scenarios, giving the speed each link is expected to sustain under those conditions.
What the outputs quantify
Together they answer two questions:
- Where is rainfall expected to reduce network performance?
- By how much?
They can be mapped in GIS to identify the links most vulnerable to rainfall-related disruption.
Mapping is the intended use
The outputs are spatial by construction, one record per link. Presented as a map they show the shape of network vulnerability directly, which is what makes them usable for prioritisation conversations with local authorities.
Where the outputs go
| Destination | Use |
|---|---|
| WP3 risk analysis | Infrastructure ageing and materials work |
| Transport demand projection | Feeding forward-looking demand assessment |
| Road resilience assessment | The baseline of network vulnerability |
| Combined risk layer | Informing policy advice to local authorities |
| Policy impact simulation | Examining alternative interventions under each future scenario |
| The DSP | Contributing to the Decision Support Process |
This is a handover point to the other handbook
The chain that begins with a rain gauge reading ends as evidence in the Decision Support Process.
That transition, from modelled and measured evidence to structured decision making, is the join between the two halves of the DARe framework.
How this relates to the POESE metrics
The resilience tool and performance metrics both quantify disruption, but they are not substitutes.
| POESE metrics | Resilience tool | |
|---|---|---|
| Derived from | Agent-based simulation | Observed data |
| Breadth | Five dimensions, 32 metrics | Speed sensitivity |
| Depth | Individual travellers and demographic groups | Every link on the Strategic Road Network |
| Best for | Understanding consequences in full | Identifying where the network is weakest |
The resilience tool covers a wider extent with a narrower measure; POESE covers a narrower extent with a far richer one.