On the eve of Thursday evenings's meeting on the already controversial restriping proposal for Portland and Park avenues, MPLS caught up with Hennepin County's transportation chief, Jim Grube, to ask about some of the more highly debated aspects of the design. The meeting to show the design is from 6:30-9 at 2400 Park Av. Here's a summary of the Q-A, including some questions raised by commenters to this blog: Q: Why cut the speed limit from 35 to 30 miles per hour? A: If the changes proposed occur, there's a potential for a different look and feel to the street and most city streets have a 30 mile-per-hour limit. Q. Would lights be retimed to the new speed limit? A. That's a responsibility of the city, but it has indicated that they will be. Q. Will forcing drivers to switch from three lanes to two as they leave downtown and also as they drive south of Lake Street increase congestion on Portland? A. There's no question that motor vehicle movement will degrade somewhat but it will remain within industry standards. Minneapolis is developing specific analysis of potential congestion changes. Q. Why would the Park and one-third of the Portland bike lanes be shifted from the left side to the right? A. Bikers alerted us to concerns about the left side lanes, and the left traffic lanes tend to have faster speeds than the right side lanes. Q. Why make bikers switch from a left side bike lane on Portland coming out of downtown to a right side lane south of E. 36th Street? A. There is significant right turn demand until south of Lake Street that creates conflicts for a right side bike lane, but that lessens farther south. Q. Where would the space taken from the third traffic lane go? A. To buffer zones for the bike lane, either between that lane and motorists under one alternative or on both sides of the bike lane to also buffer against opening car doors.