Item 6B - TNP Traffic Left Turn Lane Review Memo 5-16-2024From: Chris Edwards Sent: Wednesday, May 15, 2024 5:46 PM
To: Kevin Ferrer
Cc: Jonathan Bengfort; Ryan Jones; Robert Cohen ; Lauren LaNeave
Subject: RE: Overlook Development
Good evening Kevin,
To the best of my memory, here is a summary of our discussion. I apologize for not taking notes during the
call.
• Operation of vehicles exiting Main St. to go south on N. Carroll – Based on the left-turn lane
exhibit included in the traffic study for the development, the beginning of the 75-foot taper for
the left-turn lane is approximately 180 feet north of Main St., and the 75-foot storage for the
left-turn lane begins approximately 260 feet north of Main St. The desired lane transition distance
for 30 MPH is 180 feet. Vehicles exiting Main St. should have time to change lanes to reach the
proposed left-turn lane and utilize it for U-turns onto southbound N. Carroll. If they cannot safely
change lanes to reach the left-turn lane, they will proceed north to the median openings at
Prospect Street or Federal Way. It should be noted that the proposed left-turn for the proposed
development will provide a safer U-turn option due to the left-turn lane storage than the vehicles
would have at Prospect St., where no left-turn lane exists. I also believe that once left-turn
movements are prohibited from westbound Main St., some of the vehicles that would choose that
route today, particularly those intending to eventually proceed west on Southlake Blvd. or south on
S. Carroll past Southlake Blvd., will choose other routes to exit the Town Square area, reducing the
potential number of U-turning vehicles.
• Impacts for residents exiting the proposed development – The traffic study includes an intersection
level of service (LOS) analysis for the north driveway that includes both the left-turning and U-
turning vehicles using the left-turn lane on N. Carroll. The total number of vehicles utilizing the left-
turn lane during the PM peak hour is 63, or approximately one per minute. The LOS for vehicles
turning right from the development was determined to be LOS B, with only a 12-second delay per
vehicle, with essentially no queueing. Only 25 vehicles are anticipated to exit this driveway during
the studied PM peak hour. Prospect St. is approximately 170 feet north of the proposed
driveway. Vehicles exiting the development will experience vehicles turning left from westbound
Prospect St. as through vehicles on the southbound lanes of N. Carroll, as opposed to conflicting
turning vehicles like vehicles at the intersection of Lakewood Dr. and N. Carroll experience. In
addition, vehicles exiting the proposed development only have the option of turning right onto
southbound N. Carroll, as opposed to potentially turning left or trying to cross, as vehicles exiting
Lakewood Dr. have the option to do. This reduces the potential conflict points and, therefore, the
number of decisions the exiting driver must make.
Additional apologies that the “summary” got a bit wordy. I hope I have conveyed the information you are
interested in memorializing. Please let me know if there is anything I’ve missed that you would like
included.
Thanks and have a wonderful evening,
Chris
Chris Edwards , PE
Senior Engineer
,
Associate Principal
817.665.7111 direct | 817.713.8614 mobile | 817.336.5773 front desk
5237 N. Riverside Drive, Suite 100 | Fort Worth, TX 76137
cedwards@tnpinc.com
www.tnpinc.com