(Seattle, WA)  --  A large portion of the I-5 could someday be open only to self-driving cars.  A group of Seattle-based venture capitalists has released a timeline for their proposal to limit the highway to autonomous, driverless cars in part of Washington.  The firm Madrona Venture Group says they'd like to ban human drivers on the highway between Seattle and Vancouver, B.C. during peak travel hours as soon as the year 2040.  The group wants to get the ball rolling by immediately opening the carpool lanes to self-driving cars and later creating two lanes exclusively for self-driving cars by the year 2025.