highway improvement

例句：

1. 1. The government is investing heavily in highway improvement to improve traffic flow.
   政府正在大力投资于高速公路改善，以改善交通流量。
2. 2. The new road construction will greatly enhance the convenience of the high-speed highway.
   新的道路建设将极大地提高高速公路的便利性。
3. 3. The project aims to improve the safety and efficiency of the highway system.
   该项目旨在提高高速公路系统的安全性和效率。