Tram or bus rapid transit in a mid-sized delta city
A city of 310,000 in the Rhine-Meuse delta is appraising a 9.2 km public transport corridor from the university hospital to redeveloped docklands. Bus line 14 currently carries 8,400 passengers per day, but peak journeys take 38 minutes against a 22-minute schedule; 22% of households in the corridor have no car. Light rail would cost €210m, take three years to build, and run end-to-end in 24 minutes; it requires a 1.8 km cut through a 19th-century park and a new bridge over a flood-relief channel. Bus rapid transit (BRT) would cost €95m, be operational in 14 months, and take 29 minutes; dedicated lanes would remove 240 parking spaces from the main shopping street. The national government funds 40% of capital cost. The city’s annual operating subsidy is capped at €6m. Traders fear construction disruption; hospital staff prioritise reliability.
1. Identify two appraisal criteria that follow from the constraints in the setup and give one measurable indicator for each. Explain why each criterion is material to the decision.
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Two material criteria are reliability for captive riders and fiscal affordability for the city. Reliability indicator: 95th-percentile peak journey time, or the share of peak trips arriving within five minutes of schedule. This is material because 22% of corridor households are car-free and hospital shift workers cannot absorb a 16-minute schedule gap; BRT's dedicated lanes and light rail's segregation both improve on mixed traffic, but the size of the gain is an empirical question. Fiscal indicator: net present cost to the city after the 40% grant plus annual operating subsidy, tested against the €6m cap. This is material because the city must fund 60% of capital: €126m for light rail versus €57m for BRT. A criterion such as 'sustainability' would be too vague unless specified as CO2 per passenger-km or mode shift from cars. The two criteria conflict: light rail gives a larger reliability gain but much greater capital and operating exposure. A good appraisal states that trade-off explicitly rather than collapsing it into one score.
2. Recommend either light rail or BRT, or a phased alternative, and justify with explicit trade-offs under the €6m operating subsidy cap.
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BRT is the defensible choice unless the city can secure a larger grant or a higher subsidy cap. City capital cost is €57m for BRT versus €126m for light rail, a difference of €69m; at 8,400 daily passengers, city capital per daily rider is about €6,800 for BRT and €15,000 for light rail, before capacity benefits. BRT can open in 14 months, reducing exposure to construction-cost overrun and trader disruption. Its main weaknesses are the 240 lost parking spaces and the 29-minute journey, which may not satisfy hospital shift changes. These can be mitigated by signal priority, a replacement parking strategy, and a staff shuttle. Light rail is faster and has higher capacity, but the park cut and bridge create planning risk, and the €6m operating cap may be breached. A phased approach-BRT now, with a protected alignment for later light rail-preserves the option. The recommendation should be conditional on modelled peak reliability and a parking-impact assessment.
3. What single piece of evidence collected before the final decision would most likely reverse your recommendation? State the threshold or condition.
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The recommendation would reverse if BRT cannot achieve a 95th-percentile peak journey time below 30 minutes with signal priority, or if forecast corridor demand exceeds about 14,000 passengers per day by year 5. At that demand, BRT vehicles would bunch and the reliability advantage would disappear; light rail capacity would then dominate. A second reversal condition is financial: if the national grant share for light rail rises to 70%, the city's capital contribution falls to €63m, close to BRT's €57m, and the park/bridge risks become the main remaining obstacle. Evidence that the park cut can be engineered without losing more than 0.3 ha of mature trees, or that the flood-relief bridge can be shared with existing infrastructure, would also weaken the case against light rail. The point is to specify a threshold in advance, not to wait for opposition to force a rethink.