# Modelling the evolution of the European high-speed rail infrastructure network

## TL;DR

This paper introduces a new model to plan the future of high-speed rail in Europe, aiming to create a cohesive network that increases rail travel by 2065.

## Contribution

The novel ENGINEER model iteratively selects HSR infrastructure based on economic potential while considering network effects and budget constraints.

## Key findings

- ENGINEER identifies promising HSR investments to create a cohesive European network.
- The model predicts a rise in rail mode share from 13% in 2023 to 27% by 2065.
- Path dependency and integrated decision-making are emphasized in infrastructure planning.

## Abstract

High-speed rail (HSR) is often considered a promising and sustainable alternative for long-distance travel in the European context, aligned with Europe’s ambitious mobility and climate goals for 2050. However, a cohesive European HSR network is yet to be realised. Critically, the planning of a European HSR network requires considering how the network is to gradually evolve from its current fragmented state. We introduce an Evolutionary Network Growth model with Infrastructure and Network Effects considerations for European Rail (ENGINEER). This novel iterative network growth model selects the HSR infrastructure with the highest economic potential, continuously updating network configurations and demand patterns, subject to budget feasibility constraints. ENGINEER integrates cost estimates based on a microscopic representation and benefits estimated based on a macroscopic travel demand representation and is applied across 28 European countries. Our findings highlight the importance of path dependency and the benefits of an integrated decision-making in infrastructure planning. Model results demonstrate that ENGINEER can effectively identify promising HSR investments, yielding a cohesive and well-integrated European HSR network which leads to an increase in rail mode share per trip from 13% in 2023 to 27% by 2065.