Why are highways in Sichuan difficult and hazardous to build?

The construction and maintenance of highways in Sichuan are particularly difficult and hazardous due to the province's challenging physical geography and geological instability.1

Key factors contributing to these challenges include:

• Dissected Terrain: The province features highly uneven, rugged landscapes, including deep canyons, steep slopes, and high mountain ranges that necessitate the construction of numerous solid embankments and hairpin turns.21
• Geological Instability: The region is characterized by easily weathered rock structures, which increase the risk of infrastructure damage.1
• Seismic Activity: Sichuan is located in a highly active seismic zone where crustal compression frequently triggers earthquakes. This seismic volatility, combined with the rugged terrain, creates a constant threat of landslides that complicates both the building process and ongoing road maintenance.21

Historically, these geographic barriers made travel into or out of the province extremely difficult, relying on treacherous routes such as mountain plank roads and dangerous river passages. While significant infrastructure improvements have been made since the 1950s, the province's complex relief continues to pose significant engineering hurdles.1