Transport scenario
The second half of the framework builds a working picture of how a region moves on an ordinary day. This is the baseline against which every disruption is measured.
It has two parts.
Demand and supply
| Part | Plain English | What it contains |
|---|---|---|
| Transport demand | Who is travelling, and why | The population, their trips, and freight movements |
| Transport supply | What they travel on | The network: roads, rail, stops, routes, timetables |
Put together, these establish the normal mobility behaviour of the population in the study area. Nothing has gone wrong yet. This is the region working as intended.
That baseline matters more than it might sound. Disruption can only be measured as a departure from something, so the quality of the impact numbers at the end depends directly on how faithfully normal behaviour is represented here.
The third ingredient: behaviour
People do not carry on as normal through a heatwave. They stay in, they travel earlier, they cancel the discretionary trip.
So the transport scenario also accounts for social behavioural responses to the weather event being analysed. During a heatwave, for instance, people may choose to stay at home rather than doing leisure activities on the streets.
Why model this separately
Behavioural response changes demand before the hazard physically touches the network. Leaving it out would overstate the number of travellers exposed to the hazard, and therefore overstate the disruption.
Covered in detail
| Element | Chapter |
|---|---|
| The movement of people and goods | Transport demand |
| The physical and operational network | Transport supply |
| How travel changes under hazard conditions | Social behavioural impacts |
| Simulating the two together | Transport model |