Joint optimization of green vehicle scheduling and routing problem with time-varying speeds

<div><p>Based on an analysis of the congestion effect and changes in the speed of vehicle flow during morning and evening peaks in a large- or medium-sized city, the piecewise function is used to capture the rules of the time-varying speed of vehicles, which are very important in modelling their fuel consumption and CO₂ emission. A joint optimization model of the green vehicle scheduling and routing problem with time-varying speeds is presented in this study. Extra wages during nonworking periods and soft time-window constraints are considered. A heuristic algorithm based on the adaptive large neighborhood search algorithm is also presented. Finally, a numerical simulation example is provided to illustrate the optimization model and its algorithm. Results show that, (1) the shortest route is not necessarily the route that consumes the least energy, (2) the departure time influences the vehicle fuel consumption and CO₂ emissions and the optimal departure time saves on fuel consumption and reduces CO₂ emissions by up to 5.4%, and (3) extra driver wages have significant effects on routing and departure time slot decisions.</p></div

Comparative analysis of system performances with extra wages during overtime periods.

<p>Comparative analysis of system performances with extra wages during overtime periods.</p

Flowchart of adaptive large neighborhood search algorithm.

<p>Flowchart of adaptive large neighborhood search algorithm.</p

Optimal routes to minimize the total emissions (total emissions = 354.65 kg).

<p>Optimal routes to minimize the total emissions (total emissions = 354.65 kg).</p

The optimal routes and departure time without extra wages during nonworking periods.

<p>The optimal routes and departure time without extra wages during nonworking periods.</p

Comparative analysis of the optimal departure time between two different schemes.

<p>Comparative analysis of the optimal departure time between two different schemes.</p

A diagram of the solution of joint vehicle scheduling and routing problem.

<p>A diagram of the solution of joint vehicle scheduling and routing problem.</p

Different driver wages at different time slots.

<p>Different driver wages at different time slots.</p

The optimal routes and departure time with extra wages during nonworking periods.

<p>The optimal routes and departure time with extra wages during nonworking periods.</p

Some adjustment parameters of score.

<p>Some adjustment parameters of score.</p