Traffic analysis calls for removal of certain driveways to facilitate safety
Having taken into account the impact of the COVID-19 pandemic on traffic counts, and having analyzed vehicle patterns for safety purposes, the Kimley-Horn consulting firm has made recommendations to Sarasota County staff related to the proposed construction of a hotel and parking garage on south Siesta Key.
The firm, which has offices in Tampa and Sarasota, conducted its traffic counts on July 16, 2020, its report says. Kimley-Horn determined that only 92 extra vehicles would be associated with the seven-story, 120-room hotel and 203-space parking garage during peak afternoon drive time, the report adds.
The firm also has called for the removal of the southern right-in/right-out driveway along Stickney Point Road, as well as an egress-only driveway on Old Stickney Point Road, the report says.
“The removal of these additional driveways will improve access management and safety along both roadways,” the Kimley-Horn report adds.
Access to the parking garage would consist of a right-in/right-out/left-out driveway on Old Stickney Point Road, along with a left-in/right-in/right-out driveway on Stickney Point Road, the document notes.
Additionally, the study determined that no right-turn lane would be warranted for the hotel driveway on Peacock Road, as fewer than 80 vehicles altogether are anticipated to be in that vicinity during the afternoon peak hour after the hotel has been built.
“For the purposes of this analysis,” the report continues, “2022 was considered the [build-out] year [for the parking garage and hotel] and, thus, 2022 conditions were evaluated as the ‘future year’ scenario.”
Kimley-Horn representatives had accepted comments from Sarasota County Transportation Planning staff on July 6, 2020, while the access issues subsequently were discussed with county staff on July 16, 2020, the study points out.
County staff advised Kimley-Horn that its traffic counts might not be accurate because of “the atypical traffic patterns caused by the 2019 Novel Coronavirus (COVID-19) pandemic.”
In a July 6, 2020 letter to Kimley-Horn, Barrington Long, a technical specialist in the county’s Transportation Planning Division, pointed out that, because of the pandemic factor, Kimley-Horn could use the results of a traffic study conducted “within the last year or two” at the intersection of Midnight Pass Road and Stickney Point Road and then apply “an appropriate growth rate.”
A June 23, 2020 letter from Kimley-Horn to Long also explained that Kimley-Horn planned to calculate the traffic counts for the hotel and parking garage on the basis of rates “provided in the Institute of Transportation Engineers (ITE) Trip Generation Manual, 10th Edition.”
The resulting Kimley-Horn report — submitted to county staff on Oct. 26, 2020 — says that 30 of the additional afternoon peak-hour trips are expected to be produced by vehicles whose drivers are accessing the retail space planned on the lower level of the parking garage.
“The approximately 203-space garage also plans to support public parking,” the report also notes, by making 103 of the spaces available for people other than hotel guests and visitors to the retail businesses. Therefore, the report continues, a conservative assumption is that 50% of those 103 spaces would generate traffic during the peak afternoon drive time. That would equate to 52 extra vehicles entering the garage, the report adds, while the maximum number leaving the facility at the same time would be assumed to be 52.
Factoring in the pandemic effects
Additionally, the report explains, Kimley-Horn studied the following intersections on the basis of the methodology that county staff agreed to for the analysis:
- Parking garage driveway and Stickney Point Road.
- Parking garage driveway and Old Stickney Point Road.
- Stickney Point Road and Midnight Pass Road.
- Midnight Pass Road and Old Stickney Point Road.
- Peacock Road and Old Stickney Point Road.
- Peacock Road and the hotel driveway.
Kimley-Horn staff undertook vehicle counts between 4 and 6 p.m. on Thursday, July 16, the report notes. “Due to the impacts of COVID-19,” the report says, “the traffic count data was compared to a previous count that was performed during peak season at the intersection of [Stickney Point Road] & Midnight Pass Road in 2017. The previous count at [that] intersection … was projected to 2020 volumes utilizing three years of growth,” with Kimley-Horn projecting a “conservative growth rate” of 1.0% …”
The report points out that the volume of traffic in 2020 at the study intersections for which Sarasota County did not provide data “was approximately 22% less than the previous data (collected in 2017 and projected to 2020 traffic volumes). Therefore, the intersection count data (collected in 2020) was increased by 22% at the study area intersections.”
Further, the report says, “The vehicle counts at the study intersections were also adjusted to reflect peak season conditions,” using a Florida Department of Transportation (FDOT) peak seasonal factor for Sarasota County.
Other factors regarding the parking garage
In regard to the parking garage, the report notes that a westbound left-turn lane exists at the site of the proposed driveway on Stickney Point Road. That lane is about 300 feet long, measured from the middle of the planned driveway to the end of the turn lane, the report says. Based upon the latest FDOT Design Manual, the report points out, the westbound left-turn lane is anticipated to require 290 feet — 240 feet for deceleration and 50 feet for queuing of traffic. “Therefore,” the report adds, “the existing westbound left-turn lane along [Stickney Point Road] is anticipated to be adequate.”
Kimley-Horn also undertook an analysis to determine whether an eastbound right-turn lane for the garage should be provided on Stickney Point Road, the report says. “For a roadway with a speed limit 45 mph or less, a right turn lane may be warranted if the volumes are 80 to 125 vehicles per hour,” the report continues. However, the report notes, Kimley-Horn decided that an eastbound right-turn lane would not be necessary in this case, because the study indicated that only nine extra vehicles during the afternoon peak drive time would be using the garage.
Further, Kimley-Horn analyzed whether a westbound right-turn lane should be included for the garage on Old Stickney Point Road. Based on the anticipated future traffic volumes, the report says, that right-turn lane “was determined to not be warranted …”
Additionally, the report continues, “The garage is proposed to operate without control gates,” to allow for the free flow of entry. The structure will have either an unattended kiosk or an app-oriented system for drivers to use in paying for use of the facility, the report adds. People who would park their own vehicles in the garage, the report notes, would pay upon exiting either at a “pay-on-foot station or at an in-lane credit card reader.” Thus, a garage queue analysis found “a maximum vehicle queue” of one during the peak hour.
Moreover, the report notes, if a person were to pull up to the garage entry gate “either accidentally or changes their mind” about parking there, the lack of a gate would make it possible for the driver to enter and exit for free “within a certain time period,” 5 or 10 minutes, for example. “This will prevent vehicles from backing onto Stickney Point Road …”