Infrastructure and transportation
A capital program shows what a government plans to spend. It does not show the capacity that enters service in each year. DDA examines demand, capacity, cost, and the sequence of projects, and finds the project that must come first.
01 The delivery chain
An infrastructure project moves from a need to a service. Demand data defines the need. A study sets the scope and the cost. The project earns funding and approvals. Procurement, design, and construction follow. The asset enters service, and then it needs operating money and renewal money for its whole life.
Projects also depend on each other. A highway interchange can wait on a utility relocation. A transit line can wait on a station area plan. A road that opens before its connecting road opens serves less traffic than the forecast assumed.
02 The evidence problem
Demand forecasts drive most projects, and they carry the most uncertainty. Ridership and traffic forecasts for large projects have a record. Studies of completed projects show that forecasts often overstate use and understate cost. DDA uses that record as a reference class and asks if the case at hand differs from it with evidence.
A capital budget total mixes projects at different stages. Money for planning, for design, and for construction all appear in one figure. DDA separates them and states which projects have committed funds and which have proposals.
Cost estimates carry a stage. An early estimate has a wide range, and a later one has a narrow range. DDA states the stage and the range, and compares them with the final cost of similar projects.
Traffic counts, transit boardings, and freight volumes come from different agencies and different years. DDA records the definition and the period for each.
Operating cost is often missing from the case for a project. An asset that costs little to build can cost a large amount to run and renew.
03 Where it usually breaks
Sequence breaks the benefit. A project that delivers value only after another project completes shows no value in the years between. DDA maps the dependencies and finds the critical path.
Cost escalation breaks the budget. A project approved at one price can reach construction at a higher price. Delay increases cost, and cost increases delay when funds must be found again.
The funding cliff breaks the operation. A grant pays for construction and ends. The operating budget takes the load.
Concentrated benefit breaks the case. A project can serve a few users well and many users poorly. Average ridership or average travel time hides the split.
Freight and goods movement can break at a single chokepoint. A crossing, a port terminal, or a rail yard can limit the whole chain. DDA identifies the node with no substitute and the controller of that node.
04 What the work can produce
The work can produce a capacity-in-service schedule, a project dependency and sequence analysis, a demand-forecast test against reference classes, a cost and funding analysis with committed and proposed funds separated, a chokepoint analysis for a goods-movement chain, an operating and renewal cost view, and a set of indicators that show early if a project is slipping.
05 Connected capabilities and related thinking
This area uses Fiscal and scenario modelling, Land, infrastructure, and spatial analysis, and Evidence reconstruction. For the funding side, see Public finance and capital planning. For projects that depend on the access, see Mining and critical minerals and Tourism and resort communities.
06 Bring the question
Send the capital plan, the corridor study, the business case, or the forecast. DDA will find the project or the assumption that limits the result.