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<p><strong>Abstract.</strong> CityGML, an OGC standard, is an open data model for virtual 3D city models and includes buildings, roads, terrain, water bodies, etc. While many modules are well-developed (eg buildings, bridges, tunnels), the transportation model is, based on our consultations with various government agencies and municipalities, not sufficient for most transportation applications. We propose in this paper several improvements to the CityGML v2.0 Transportation module, and to the previous efforts for improving it. Our additions are based on the consultations we had, and on the use-cases that were identified. We argue that the following changes are necessary: A) multi-LoD modelling of roads, B) carriageway representation, C) detailed intersection modelling and, D) introducing waterways as a new sub-class.</p>

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Estimation of the time needed to evacuate a population from a threatened area in case of a disaster is one of the main issues in the design of an evacuation plan. The challenge is to develop a strategy that optimally uses the network capacity to minimize the total evacuation time. In this paper, the impacts of various departure time spans on evacuation time and network performance are investigated with a microscopic traffic simulation model. The network performance has been analyzed with the use of the macroscopic fundamental diagram (MFD). Although the MFD usually shows a decrease in travel production after a peak is reached, this is not the case in the simulation of evacuation scenarios. The outflow of the network remains constant because it depends on the capacity of local bottlenecks upstream of the limited number of destinations, but the number of vehicles in the network increases because of an increase in congestion. Although the overall network performance is insensitive to the evacuation time spans, it is observed that for shorter evacuation time spans, internal gridlock effects cause lengthy delays for specific groups of drivers, who, it turns out, are unable to leave the network in time. The use of a simulation study in combination with an MFD can therefore identify the routes used and the bottlenecks on these routes leading to the destinations, while the maximum production level (defined as the number of arrivals, determined in the MFD) indicates the optimal level of demand.