Research Article
Urban Freight Management with Stochastic Time-Dependent Travel Times and Application to Large-Scale Transportation Networks
Table 1
Notations and variables.
| Type | Symbol | Definition |
| Objective function quantities | | The number of vehicles out for service | ST | Total schedule time | TT | Total travel time | WT | Total waiting time | SVT | Total service time |
| Sets | | Set of starting nodes of all vehicles | | Set of end nodes of all vehicles | | Set of all customer nodes | | Set of starting nodes and customer nodes | | Set of customer nodes and end nodes | | Set of all nodes | | Set of all customers | | Subset of set | | Set of links that are present in the networks |
| Inputs and parameters | | The number of time intervals | | Time interval | | An infinite number | | Service time of customer node | | Delivery demand of customer node | | Time window of depot | | Time window constraint of customer node | | Capacity of vehicle |
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Decision variables | | Vehicle’s arrival time at node | | , if any vehicle occupies at time ; otherwise | | Travel times of the optimal path from customer node i to customer node j at departing time interval | | , if vehicle departs from customer node to customer node at time interval ; otherwise | | , if customer node is visited by vehicle ; otherwise, |
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