What Do the Traffic Studies Tell Us Vis-a Vis the NDC Site Plan?

by Roger Schlegel

1. The traffic studies are extremely complex in terms of assumptions, methodologies, measurements, and recommendations. The City Council should seek expert review of these studies before moving to vote on the NDC site plan because that site plan appears to be dependent on reconfiguring the intersection. To be clear, there is no estimate of the cost of such a reconfiguration, nor is there a sense of who would pay for it, nor is there a sense of when or whether SHA would approve such a reconfiguration.

2. The site plan consideration and the exploration of a reconfigured intersection are not entirely separate, “parallel-track” activities. While it may be true that background traffic soon to come online will push the performance of existing Junction intersections just below acceptable levels of service, it is also true that the studies characterize the site plan’s design and traffic generation as necessitating an intersection reconfiguration. The City Council should be clear in recognizing that the new development is the main impetus for reconfiguring the intersection.

3. The projected improvements in traffic flow associated with the reconfigured intersection appear to rely on the elimination of an all-red crossing phase for pedestrians (both at the main intersection and at the Philadelphia Avenue intersection). They also require the elimination of the new crosswalk (and signal) at Grant Avenue. The City Council should consider carefully whether these changes would be sustainable after the construction of a new development that would increase north-south pedestrian movement and possibly encourage jaywalking.

4. The lay-by as designed is apparently too close to the stop line at the existing intersection. Moving that lay-by back would eliminate a chunk of the small proposed public space, increase the length of the loading/unloading path for trucks, and possibly make the development less attractive to tenants. The proposed reconfiguration of the intersection makes it possible for the lay-by to remain in the NDC site plan. Alternative concept plans exist which would provide off-street deliveries. The City Council should push NDC further to see whether it is open to an alternative design that doesn’t rely on a lay-by.

5. The studies did not address the functionality of the lay-by when multiple trucks arrive simultaneously, the possibility of double-parked trucks, the impact on streets and roads around the area if trucks are expected to circle around and re-attempt delivery or pick-up, or the impact on emergency vehicle movement. The City Council should seek answers to such questions before voting on the NDC site plan.

6. The NDC development would appear to increase traffic at the Junction by up to 11% during the AM peak-hour and by up to 24% at the PM peak-hour. This implies that the NDC development, not other increasing background traffic, would be the primary contributor to the projected failing performance of the Junction intersections. Again, the City Council should not marginalize the traffic impact of the new development as it deliberates about the site plan.

7. Big questions remain about the location and functionality of the driveway to the parking garage. The City Council should be certain that this is a viable design before passing the question on to reviewing agencies. In particular, if the City pushes ahead to try to reconfigure the intersection, it eliminates a possibly more viable location for a parking garage driveway, which would be on line with the existing signal at Carroll/Ethan Allen/Grant. It is clear that there will be significant queues to exit the garage during the peak PM period, even without a restaurant use. The peak AM projected queue does not assume the presence of a coffee shop on-site or of a grocery store open during those hours. There are real questions about sight lines and pedestrian and cyclist safety. The TTG study did not clarify how left turns into and out of the garage would be affected by queues in the travel lanes.

8. The future fate of the Turner Building needs careful consideration before any vote on the NDC site plan. Setting aside the impact of the site plan on the Co-op (as this is subject to the current mediation process), the City Council should consider closely how the proposed lay-by and the proposed intersection reconfiguration, would affect the future utility of the Turner Building (which the Co-op currently rents). In addition, the City should seek independent professional advice about the long-term viability of a lay-by arrangement for future tenants of the proposed NDC development. In particular, given the value that a grocery store provides as an anchor for a business district, the City should find out whether any grocery store would be attracted to a site that relies on a lay-by for all deliveries and trash handling. Beyond this, the City should investigate how suggested relocation of the entrance driveway and possible reactivation of the loading dock would impact the capacity of the Turner Building’s parking lot.

9. The City still knows very little about the present state of cut-through traffic at the Junction. The City-commissioned study (AMT) provided measurements of cut-through traffic only on one route involving the length of Columbia Avenue. The studies provided no data on present cut-through traffic in other neighborhoods or on projections of cut-through traffic resulting from the proposed development (cars as well as trucks). It seems that it would be crucial for the City Council to get a clear understanding of present and projected cut-through patterns before voting on the NDC site plan.

10. The size of the proposed public space in the NDC site plan has been a huge issue. In response to criticisms that the proposed space is too small for community events, it is frequently noted that B.Y. Morrisson Park is a more appropriate place for such events. The City Council should think carefully about what the elimination of B.Y. Morrisson Park would mean for the Junction in terms of its potential as a place for public events and gatherings. A mid-intersection “pedestrian refuge” triangle should not be characterized as a true park space. Also, the loss of the four public parking spaces on the north side of B.Y. Morrisson Park should not be ignored as an impact of an intersection configuration.

11. The businesses and residents on the north side of the Junction should be given ample time to review and respond to the traffic studies before the City Council votes on the NDC site plan. Many of these businesses are reliant on convenient parking and easy pedestrian movement for their viability. The projected queue lengths and delay times for exiting the new parking garage may be of concern to north-side businesses, along with changes in pedestrian crossing routes, the elimination of B.Y. Morrisson Park, and the elimination of the all-red pedestrian crossing phase. The City Council should also consider a scenario whereby Manor Circle and other nearby neighborhoods choose to have residential permit parking — how would such a change impact the functionality and convenience of the new parking garage, and would north-side clients and customers be willing to “migrate” to the new parking garage?

12. Stepping back from the details a bit, one can imagine that if the site plan (or something like it) gets built — without or without an intersection reconfiguration — it will become clear that the development, along with Turner Building, needs a rear path for cars to circle around and for trucks to unload (a.k.a. an “alley”). The City Council should closely consider whether the creation of an alley is an eventuality and, if so, confront that potential need before voting on the NDC site plan.

In summary, it is very important for the City Council to take the necessary time to examine the implications of the traffic studies and address unanswered questions before taking any vote on the NDC site plan.

For an extended Issue-by-issue Analysis of the Traffic Studies Vis-a-Vis the NDC Site Plan in table form, addressing 20 specific issues, go to the google doc at this link.

Author: Susan Katz Miller


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