HomeMy WebLinkAboutSD-22-10 - Supplemental - 0500 Old Farm Road (50)1
Andrew Gill
From:Roger Dickinson, PE, PTOE <Roger.Dickinson@tcevt.com>
Sent:Thursday, October 6, 2022 9:31 AM
To:Andrew Gill
Cc:Jeremy Matosky, P.E.; Evan Langfeldt
Subject:RE: Contract and Traffic Update
Hi Andrew,
As requested, we are writing to provide our thoughts regarding Items 7 and 8 on pg. 13 of the Staff Report for the
October 6th DRB meeting.
Item 7:
The Staff Report notes that BFJ’s preliminary plat recommendation was to delay installation of exclusive turn lanes until
movements reach LOS E.
Installing left‐turn lanes at these two intersections will not require any physical construction or roadway
widening, but rather only installing new pavement markings.
It is unclear what movements are being referred to here. If it is the left‐turn movement turning off from
Kimball Ave onto Potash Rd or Old Farm Rd, our experience is that the left‐turn movement from a major street
at an unsignalized intersection rarely experiences LOS E.
BFJ’s recommendation makes more sense If the LOS E being referred to here is experienced by the movements
exiting Potash Rd or Old Farm Rd. Looking at the intersection capacity analysis results contained in Appendix M
for Old Farm Rd in the March 30, 2022 TIA, it is apparent that LOS E will not be created by the proposed
residential development, but will more likely occur when the installation of a traffic signal becomes warranted
by future commercial development in the C1‐LR zone. Although the TIA did not include any unsignalized
intersection capacity analyses at the Potash Rd intersection (Appendix N) a similar situation will exist there as
individual lots are developed.
The primary benefits of installing left‐turn lanes on major streets at unsignalized intersections are to provide
for increased safety (reduced rear‐end collisions) and to maintain efficient through traffic flow (by preventing
queues from forming behind left‐turning vehicles waiting to make a left‐turn onto the side street). The
corresponding reductions in delays and traffic congestion are typically rather small.
In any event, the left‐turn lanes on Kimball Ave need to be installed concurrently with future traffic signals for
operational purposes.
Item 8:
As was requested, the updated March 30, 2022 TIA included analyses of future connection between Tilley Drive and
Kimball Ave, which Potash Rd will be a segment of. The future traffic congestion benefits of that future connection are
given in given in Table 13 of the foregoing TIA. Based on those results, it became our professional opinion that future
transportation‐related improvements would be better focused on implementing a future Tilley Drive connection rather
than on widening Old Farm Rd to provide an additional turn lane exiting onto Hinesburg Rd. Thus, that original
recommendation was removed from the updated March 30, 2022 TIA.
Hope the above helps with tonight’s meeting. Feel free to call me should you have any questions or if we may be of
additional assistance.
Roger
2
tcevt.com
Roger Dickinson, PE, PTOE
Senior Engineer/Project Manager
e. Roger.Dickinson@tcevt.com
p. 802.879.6331 x118 | c. 802.373.7135
478 Blair Park Road, Williston, VT 05495
42 Mapleville Depot, St. Albans, VT 05478
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