Officials on Thursday announced a $30 million modernization project for the Chicago Transit Authority’s Purple Line.

The Purple Line Express project will be the largest for the 100-year-old rail in more than 40 years.

The modernization project will restore tracks between the Jarvis and Lawrence stations, which officials hope will give riders a smoother, faster, and more reliable service and remove several “slow zones.”

The modernization project is the latest improvement expected on the Purple Line and follows a number of projects in the last two years, including track upgrades between Howard and Linden in 2013 and track improvements underway between Armitage and the Merchandise Mart.

Preliminary work begins July 20 with more construction starting next month. The project is expected to end by Thanksgiving, weather permitting.