Table 5 Comparison regarding sustainable development indicators

Share of feasible public mobility options (3.3.1)

Social

With twice as many rides supplies for Option II versus Option I and without the restriction to the residual set R, there is a substantially higher accessibility and availability gain. The estimated share of feasible \(\left( {i,j,\tau } \right)\) increases by 19 rather than 6 percentage points

Budgetary requirements (3.3.2)

Economic

Assumption: At equilibrium state and assuming \(\tilde{\pi }^{^{\prime}} = 2\) and a fare similar to the current single ticket tariff; transaction costs, particularly costs of running a matching platform and customer service, still have to be included

Option I: For more populated territorial type 6, the subsidy could be fully recovered by levying a fixed fare of €2/Person and €.20€/Pkm. For type 7, a tariff of €2 fixed and €.25€/Pkm would still generate a deficit of €4.4 M p.a

Option II: The compensation amount for the provider side can be fully compensated with the following pricing below the public transport tariff: Type 6: fixed fare €1/Pers.,€.1/Pkm; Type 7: 2€/Pers., €.2/Pkm

Balance of external costs and GHG emissions (3.3.3)

Environ-mental

In the equilibrium state, assuming \(\tilde{\pi }^{^{\prime}} = 2\), the detours of similar size for Option I and II would cause external costs^a of about €1.3 M and a carbon footprint of about 1,300 tons of additional CO₂ emissions (Ø150g/Veh.km). Nonetheless, there would be a net saving in emissions if only 22% (Option I) or 11% (Option II) of the rideshare passengers were former solo car users. Assuming further that unit accident costs of 3.5 €-cent/passenger kilometer have to be added for every additional passenger taken. The total accident cost per annum \(\widetilde{(\pi }^{^{\prime}} = 2)\) would amount to €2.8 M (Option I) and €6.0 M (Option II)

User benefits of elective demand (3.3.4)

Economic

The annual user benefit at \(\tilde{\pi }^{^{\prime}} = 2\) for Option I was calculated at €10.5 and €15.1 M for Option II. (Value of Time €8/hour, without considering the benefit from omission of transfer needs)

Market share of collective modes (3.3.5)

Environ-mental

Originating from a high solo car share, Option I is confined to the residual \({\text{R}}\). At equilibrium point there is an increase of 46%. There is not change for Option II, as the DRT would be operated independently. At equilibrium point, the demand volume is 1.15 times the previous FRS. Due to modal shifts, the market share ratio DRT:FRS will be 1.5

Operational efficiency of on-demand services (3.3.6)

Economic

Even with an equal passenger count per ride, the factual car occupancy level (22) differs much between Options I (1.24) and II (1.47). The reason is that in Option II ridesharing can be offered on virtually all routes and fulfilment time windows without regard to public transport, resulting in lower detour factors