We initiate the study of dynamic traffic assignment for electrical vehicles addressing the specific challenges such as range limitations and the possibility of battery recharge at predefined charging locations. We pose the dynamic equilibrium problem within the deterministic queueing model of Vickrey and as our main result, we establish the existence of an energy-feasible dynamic equilibrium. There are three key modeling-ingredients for obtaining this existence result: * We introduce a walk-based definition of dynamic traffic flows which allows for cyclic routing behavior as a result of recharging events en route. * We use abstract convex feasibility sets in an appropriate function space to model the energy-feasibility of used walks. * We introduce the concept of capacitated dynamic equilibrium walk-flows which generalize the former unrestricted dynamic equilibrium path-flows. Viewed in this framework, we show the existence of an energy-feasible dynamic equilibrium by applying an infinite dimensional variational inequality, which in turn requires a careful analysis of continuity properties of the network loading as a result of injecting flow into walks. We complement our theoretical results by a computational study in which we design a fixed-point algorithm computing energy-feasible dynamic equilibria. We apply the algorithm to standard real-world instances from the traffic assignment community illustrating the complex interplay of resulting travel times, energy consumption and prices paid at equilibrium.

Modern scientific experimental facilities such as x-ray light sources increasingly require on-demand access to large-scale computing for data analysis, for example to detect experimental errors or to select the next experiment. As the number of such facilities, the number of instruments at each facility, and the scale of computational demands all grow, the question arises as to how to meet these demands most efficiently and cost-effectively. A single computer per instrument is unlikely to be cost-effective because of low utilization and high operating costs. A single national compute facility, on the other hand, introduces a single point of failure and perhaps excessive communication costs. We introduce here methods for evaluating these and other potential design points, such as per-facility computer systems and a distributed multisite "superfacility." We use the U.S. Department of Energy light sources as a use case and build a mixed-integer programming model and a customizable superfacility simulator to enable joint optimization of design choices and associated operational decisions. The methodology and tools provide new insights into design choices for on-demand computing facilities for real-time analysis of scientific experiment data. The simulator can also be used to support facility operations, for example by simulating the impact of events such as outages.