Title
Consider/Discuss/Act on an Ordinance to Establish the Speed Limit along Trinity Falls Parkway from Laud Howell Parkway to Weston Road (FM 543) within McKinney
Summary
COUNCIL GOAL: Operational Excellence
(2E. Continuously Provide a High Level of Customer Service to our Citizens)
MEETING DATE: July 20, 2021
DEPARTMENT: Development Services/ Engineering
CONTACT: Robyn Root, P.E., P.T.O.E., Traffic Engineer
Thuan Huynh, P.E., Transportation Engineering Manager
RECOMMENDED CITY COUNCIL ACTION:
• Approval of the Ordinance.
ITEM SUMMARY:
• This Ordinance amends Section 62-117 of the Code of Ordinances to establish the speed limit of Trinity Falls Parkway between Laud Howell Parkway to Weston Road (FM 543) at 45 mph.
BACKGROUND INFORMATION:
• The construction of two additional travel lanes of Trinity Falls Parkway has recently been completed from Laud Howell Parkway to Weston Road, prompting the need to reevaluate the posted speed limit. The additional of these lanes have established Trinity Falls Parkway as a new four-lane divided arterial.
• When developing a recommendation for a speed zone along a corridor, the following are some of the factors that should be considered:
o The 85th percentile speed of free-flowing traffic.
o Roadway characteristics, grade alignment and sight distance.
o The design speed of the roadway.
o The established speed limit on adjacent sections of the same roadway.
o Roadside development and environment.
• In April 2021, a speed study was conducted along the corridor in a couple different locations that resulted in an 85th percentile speed that averaged approximately 58 mph.
• The design speed of Trinity Falls Parkway is 45 mph which limits the sight distance provided at any vertical curve at a 45 mph design speed. With existing driveways, it can be a challenge to maintain the necessary sight distance along at higher speeds. On a hill located near the 3500 block of Trinity Falls Parkway, Staff installed a warning sign of an approaching driveway to maintain the sight distance.
• The posted speed limit on Trinity Falls Parkway, north of Weston Road is 45 mph as the posted speed limit of Laud Howell Parkway.
• Trinity Falls Parkway has been constructed as a four-lane divided roadway, but there is little roadside development from Laud Howell Parkway until the roadway extends into the Trinity Falls MUD at this time.
• Although an 85th percentile speed was near 58 mph, the design speed of the corridor is 45 mph limiting the available sight distance at the vertical curves. Thus it is recommended that the posted speed limit for Trinity Falls Parkway be established at 45mph.
FINANCIAL SUMMARY:
• None
BOARD OR COMMISSION RECOMMENDATION:
• N/A