Microsoft is planning to expand its Redmond, Washington headquarters, adding between 10,000 and 20,000 new employees—plus the parking garages that will be needed to accomodate their cars. And the company is offering to pay $30 million for transportation and infrastructure improvements, including $15 million for a bridge construction project, to help compensate for the increased traffic the expansion will generate.

The $30 million offer may seem like a generous gesture, in an era in which it seems de rigeur for major companies to demand tax concessions from local governments before they’ll agree to add this many jobs.

But here’s some context. If the company hires 20,000 new people at its Redmond campus, and they mostly drive alone to work, that would add up to 40,000 one-way commutes per day into Redmond. Now, one lane of interstate highway can carry about 2,000 cars per hour. So the increased traffic would be enough, in theory, to clog a 4-lane highway for 5 consecutive hours.

  • That’s obviously an overestimate of how much traffic would actually be generated. The company apparently will be creating only about 8,500 new parking spots during its expansion—enough for 17,000 one-way commutes. Some employees would get to work on public transit, some by foot or bicycle, some in carpools. (Plus Microsoft has the reputation for attracting the kind of people who literally sleep in their office—so some people may practically live on the campus.) And the traffic would be spread out over many hours, and likely over many streets—some of which already have some extra capacity.

    But it’s at least an indication that, at $30 million for mitigating traffic impacts, Microsoft is getting off pretty cheap. And it’s also worth noting that, according to former Microsoftie, current Sightline supporter and King County Transit Advisory Committee member Anirudh Sahni, the company’s support for alternatives to the car has been mixed, at best.

    Update: Just to be clear, Anirudh is by no means the only Softie trying to work with the company to improve its transportation policies—there are lots of current and ex-employees working with the folks at Microsoft who are in a position to improve the situation.