Optimal Low Emission Zones scheduling as an example of transport policy backcasting
Asmae Alami, Vinith Lakshmanan, Antonio Sciarretta
TL;DR
This work tackles LEZ scheduling to meet horizon CO2 targets while minimizing scrapped vehicles. It proposes a backcasting framework that fixes a target emissions level $\bar{E}$ and derives policy schedules, solved as a constrained optimal control problem using a genetic algorithm. In the Île-de-France case, the approach yields concrete LEZ schedules with substantial emission reductions; for example, targeting $E(T)=471$ ktCO$_2$ and $R=5.2\times10^6$ disposals achieves a 92% reduction relative to $E(0)$ and disposes about 78% of the initial thermal stock $S_1(0)$. The study demonstrates the feasibility of backcasting for transport policy design and outlines avenues for refinement, including finer spatial granularity, explicit thermal vehicle types, improved disposal dynamics, and integration with complementary measures such as incentives for electric vehicles and public transport improvements.
Abstract
This study presents a backcasting approach that considers the passenger car fleet dynamics to determine optimal policy roadmaps in transport systems. As opposed to the scenario-based approach, backcasting sets emission reduction targets first, then identifies policies that meet the constraint. The policy is the implementation of Low Emission Zones (LEZs), in the Ile-de-France region as a case study. The aim is to minimize the number of scrapped vehicles due to LEZs under CO2 emission targets and to deduce an interdiction schedule of polluting vehicles by 2050. To explore potential solutions, we use a genetic algorithm that provides a first insight into optimal policy pathways.
