Sound Transit | 38,363 followers on LinkedIn. Connecting more people to more places. | Sound Transit is transforming how the Central Puget Sound region moves by planning, building and operating regional transit systems that give millions of riders an alternative to sitting in traffic. As the agency prepares for nearly a million new Central Puget Sound residents by 2040, transit services are expanding to meet today’s growing needs. Thanks to voter approval of the largest mass transit expansion in the region’s history, Sound Transit’s light rail system will grow to four times the size it is today.