I remember that sign, but I believe it was there because there was a dedicated (and separated) lane for left-turning traffic. With the new design (with bicycle accommodation) that dedicated left turn lane went away and now left turns must now be done at the intersection where they used to be prohibited. I hope I'm not misinterpreting the complaint.

Traffic - KC (Permits) assigned this issue to Traffic - PB (Engineering)

There IS a designated left turn lane. There is NO bicycle lane in the turn from Mass Ave. to Peabody, but there is a bicycle lane as soon as the turn is made onto Peabody. What I would like to see happen is that the "No Left Turn" icon sign be placed over the center lane where it had been positioned before the improvements. That means that two lanes of Mass Ave would clearly be directed into Harvard Sq. and only the "Left Turn Only" lane which already has adequate signage would feed into Peabody and the underpass to Cambridge and Broadway Sts.

Another, and possibly better, solution to the situation would be to make the center lane Both a straight ahead And a left turn lane as traffic on Garden St. is directed through this interchange toward Peabody and toward the underpass to Cambridge ad Broadway Sts.

Thank you for reporting your concern to City of Cambridge via Commonwealth Connect. We have reviewed the information you provided our staff and will be investigating this issue further.

Mr. Winters is correct that the left turns were previously a completely separate movement that was separated by a median. Left turning vehicles were not controlled by this traffic signal, they didn't stop until the signal at Peabody Street, and therefore the No Left Turn sign did not apply to them, only to the vehicles still on Mass Ave southbound. However, since the left turns are now part of this intersection and controlled by this signal, we can not reinstall a No Left Turn sign here. A No Left Turn sign does not apply only to the lane that it is most aligned with. A No Left Turn sign applies to the entire intersection approach that it is facing, so if this sign were reinstalled here, even vehicles in the Left Only lane would not legally be allowed to turn left. The sign and the lane markings would be in direct conflict, so this sign can not be installed here. I hope my explanation makes sense.

What we can do, however, is look into options to more clearly communicate the movements that drivers are permitted to make from each lane. We will look into whether left turns should be permitted from the center lane, and if so we will install new signage and lane markings. If the permitted movements are going to remain the same, we will look into installing additional signage and/or lane markings to indicate that as well. Please feel free to contact the Traffic Engineering Division directly by phone or email from our website at www.cambridgema.gov/traffic/contactforms/generalfeedback.

Just a follow up questuib re your response to my post, for which I thank you. If I make a left turn from the center lane at the interchange of MA Ave and Peabody, would I be in violation of a traffic regulation or not?

Regards