Amazon made an important investment in Seattle, and it highlights a key issue for HQ2

AP/Elaine Thompson

Seattle has an Amazon-branded streetcar.

• Amazon made a $1.5 million investment in bus infrastructure in Seattle.
• The investment will increase bus frequency on some routes that Amazon employees use to get to work.
• Public transit has been a big sticking point for cities as they fight for the chance to host Amazon's second headquarters, HQ2.

Amazon is making another major investment in public transit.

King County, Washington, announced last Wednesday that the online retail giant would be investing $1.5 million in increasing bus frequency in the area. The money will help to add 22 more weekday bus trips for a period of two years on some of the city's busiest routes. That's equal to room for 1,700 more riders.

"Adding 12,000 hours of additional bus service across the county and city's busiest routes will benefit all King County and Seattle residents," John Schoettler, head of real estate at Amazon, said in a statement. "More than half of our employees get to work in ways other than a single occupant vehicle - including more than 20 percent that take the bus. We are excited to see the increased capacity, and will continue to work with Metro and the City of Seattle to find innovative solutions that provide long-term transit options for the region."

Amazon has paid for $60 million worth of public transit for its employees since 2014. The company previously supported public transit in the region by investing $5.5 million in Seattle's streetcar in 2012.

The company has stated that public transit is one of its priorities for selecting a location for its second headquarters. Earlier this year, Axios reported that Amazon "froze out cities with poor public transit" when the company selected its shortlist of potential cities.

Amazon has been blamed for contributing to traffic congestion in Seattle as it has grown rapidly in the city. The company clearly wants to avoid a repeat of the problem as it makes a fresh start in a new city.