Serious concerns about proposed roundabout
To the editor:
I wrote the following letter to the Sanibel City Council and city’s administrative staff on Feb. 3 regarding the proposed roundabout at Causeway Boulevard and Periwinkle Way:
I am a full-time Sanibel resident, and I am writing regarding the proposed Periwinkle Way/Causeway Boulevard Roundabout. I thank city council, City Manager Sousa, city staff, and Kimley-Horn engineers for the hard work they are putting forth to address the city’s critical traffic congestion issues. I met with City Manager Souza, Planning Director Paula McMichael, and Kimley-Horn officials in January to review information/plans for the Periwinkle Way/Causeway Boulevard roundabout. It is clear that city council, City Manager Souza, city staff, and Kimley-Horn are working in good faith with all stakeholders to address the city’s critical traffic congestion issues.
My career experience is in developing commercial real estate throughout the United States, working in partnership with state and local governments in the analysis, design, engineering, financing, and construction of public roadway improvements. I worked on numerous projects in Caramel, Indiana, and Dublin, Ohio, two cities that use roundabouts as effective traffic management tools. Carmel, Indiana, has over 150 roundabouts and is considered “America’s Roundabout Capital.” I am a big fan and proponent of roundabouts under the right circumstances. However, after reviewing information and plans for the Causeway Boulevard/Periwinkle Way roundabout, this memo is offered to express very serious concerns regarding the proposed roundabout and is organized as follows:
– Traffic and Roundabout Issues
– Other Issues
– Requested Action
SECTION I: TRAFFIC AND ROUNDABOUT ISSUES
1. Roadway capacity and traffic congestion.
a. The key traffic congestion issue for Sanibel is that under normal conditions (non-hurricane recovery), more vehicles come and go on the causeway and Periwinkle Way than can be handled by this roadway system because both roadways have only one lane in either direction.
b. Residents, visitors, and businesspeople accept this “normal traffic congestion” as the price we pay for Sanibel to remain a beautiful, unique, and protected sanctuary island.
c. Since Hurricane Ian, temporary conditions, including increased traffic due to the large number of construction trade and other hurricane recovery vehicles, causeway reconstruction work, and a 20 mph causeway speed limit, have caused traffic congestion to increase above normal non-hurricane recovery conditions.
d. The worst traffic conditions occur on weekdays in the late afternoon/early evening when construction trade vehicles exit the island, with many repeated instances of traffic grinding to a halt.
e. Residents and businesses are asking city council to do something to alleviate the additional above-normal traffic congestion; therefore, a Periwinkle Way/Causeway Boulevard Roundabout has been proposed as the solution.
2. The proposed roundabout will fail.
a. It is an established fact that small roundabouts cannot handle high-volume traffic.
b. The proposed Periwinkle Way/Causeway Boulevard roundabout is too small to handle Sanibel’s high traffic volumes and will fail on day one due to these reasons:
i. A vehicle within the roundabout circle always has the right of way.
ii. When the roundabout circle is filled with vehicles constantly entering the roundabout from one direction, no vehicle may enter the roundabout from any other direction.
iii. To handle high traffic volumes, the traffic circle circumference, or overall size, of the traffic circle must be large enough to create gaps between vehicles traveling within the traffic circle.
iv. Vehicle spacing gaps are necessary so vehicles from all directions can safely enter the roundabout traffic circle.
v. Without vehicle spacing gaps, the high-volume line of traffic “takes over” the traffic circle, exclusively maintains the right of way, and constantly blocks traffic in all other directions from entering the roundabout; this is considered “roundabout blockage.”
vi. Roundabout blockage creates excessively long wait times and traffic backups for those vehicles that wish to enter the roundabout from the lower volume traffic direction.
3. How will the small roundabout make current traffic congestion much worse?
a. Roundabout blockage: Heavy late afternoon traffic exiting the island eastbound on Periwinkle Way (which has the right of way) will continually fill the roundabout, preventing traffic from all other directions from entering it.
b. Gridlock will occur from the northeast Causeway Boulevard merge lane.
i. With a roundabout, similar to the existing four-way stop intersection, residents, visitors, and construction vehicles leaving the island from Lighthouse Beach and the neighborhoods east of Lindgren Boulevard travel west along Periwinkle Way without entering the roundabout circle. Instead, these vehicles utilize the bypass lane and compete in one of two lanes to merge into the single-lane Causeway Boulevard.
ii. The high traffic volume merging from two lanes into one, combined with slow causeway traffic, will back up traffic into the roundabout circle, creating a gridlock condition that will block all traffic from Periwinkle Way (in both directions) and Lindgren Boulevard from entering the roundabout, creating “roundabout gridlock.”
c. The proof is in the drawings. The Roundabout Looking Northeast aerial drawing from Kimley-Horn at the Dec. 3 city council presentation clearly shows how roundabout blockage will occur from the traffic circle being constantly filled with eastbound Periwinkle Way traffic. The aerial drawing also depicts the roundabout gridlock that will result from northeast Causeway Boulevard merge lane back-ups.
d. Gridlock for eastside traffic.
i. Residential housing is highly concentrated on the eastside — A map of Sanibel shows that residential housing density is high, and disproportionality concentrated on the island’s eastside.
ii. Eastside neighborhoods will experience gridlock — High housing density from the Beechview neighborhood east to Lighthouse Park will increase current traffic headaches.
1. East end traffic — Residential traffic from the east that moves west along Periwinkle Way will be blocked from entering the roundabout circle and, therefore, cannot travel west along Periwinkle Way.
2. East Gulf Drive/Lindgren Boulevard traffic — Like the east end, vehicles from visitors, construction trades, and the many residential neighborhoods along East Gulf Drive will travel Lindgren Boulevard to the roundabout; due to roundabout blockage, these vehicles will be unable to enter the roundabout circle and will not be able to exit the island or to travel west on Periwinkle Way.
e. Severely limited access to restaurants and other Periwinkle Way businesses.
i. With the new roundabout, the current condition of Periwinkle Way weekday traffic backing up from Lindgren Boulevard to Casa Ybel Road during the afternoon/early evening will be replicated.
ii. Eastside residents/visitors who wish to go to a restaurant for dinner will need to travel west along Gulf Road to Tarpon Bay Road, and due to Periwinkle Way traffic back-ups, will not be able to travel east on Periwinkle Way; therefore, these residents/visitors will be limited to restaurants and other businesses located on Tarpon Bay Road, Palm Ridge Road, or in Captiva.
iii. Traffic gridlock in the afternoon and early evening will continue negatively impacting demand for restaurants and other businesses on Periwinkle Way.
f. Traffic control officers will be required.
i. Traffic “metering” lights will not address roundabout blockage created by high volume non-stop eastbound Periwinkle Way traffic and roundabout gridlock from the northeast Causeway Boulevard merge lane. As with highway on-ramp metering lights, drivers will ignore the metering light and enter the roundabout at will, causing further gridlock.
ii. Traffic control officers or four-way traffic signals will be required to keep roundabout blockage and roundabout gridlock from occurring, defeating the entire purpose of the roundabout.
SECTION II: OTHER ISSUES
1. A proper traffic impact analysis has not been performed.
a. For local governments to properly evaluate a significant traffic control measure such as a roundabout, a complete traffic impact analysis (TIA) is a required standard operating procedure.
b. A proper TIA will present a thorough analysis comparing all intersection traffic movements and all intersection wait times during AM/PM peak hours for the subject roundabout, plus the same analysis for six to eight key intersections.
c. The TIA will present the above traffic analysis/comparison for three points in time: today, opening day, and 10 years after opening day (the “horizon year”).
d. The Dec. 3 Kimley-Horn Causeway Boulevard at Periwinkle Way Intersection Evaluation city council presentation.
i. Has no TIA as part of the intersection evaluation.
ii. Presents two data charts, Intersection Control and Evaluation (ICE) and VISSIM Results.
iii. The ICE data is a generic “check the box” requirement from the Florida Department of Transportation and does not evaluate whether the proposed roundabout will alleviate or increase Sanibel’s peak-volume traffic congestion.
iv. The VISSIM analysis presents data showing that the average vehicle speed in current intersection traffic is 6 mph, while the average vehicle speed in a roundabout exceeds 12 mph.
v. If average VISSIM roundabout and intersection speeds are calculated throughout the day rather than at AM/PM peak hours, they are of little value as they do not indicate how the proposed roundabout will perform when traffic congestion is at its worst.
vi. Overall, the VISSIM analysis is a very limited tool. It is not particularly useful as it analyzes only one intersection and does not break down wait times for each intersection movement.
vii. Further, focusing on the issue of afternoon/early evening traffic congestion due to construction and visitor traffic exiting the island, the VISSIM analysis states that the average speed of current traffic in the Periwinkle Way/Causeway Boulevard intersection is 6 mph; this finding is difficult to reconcile against observed traffic conditions.
1. During almost every weekday from 4:30 p.m. to 5:30 p.m., with traffic control officers managing traffic flow, traffic exiting the island will come to a standstill in the intersection causing intersection gridlock.
2. Intersection gridlock is not due to intersection control being performed by traffic control officers.
3. Intersection gridlock occurs due to backups from (i) northeast Causeway Boulevard merge lane traffic and (ii) the large volume of slow-moving causeway traffic exiting the island.
viii. Roundabout intersection speeds/gridlock.
1. The new roundabout will experience afternoon/early evening intersection gridlock due to Causeway Boulevard merge lane backups and heavy causeway traffic volumes.
2. This condition makes the Kimley-Horn estimate of a 12-plus mph average roundabout speed a finding that is hard to reconcile with observed weekday afternoon/early evening high-volume traffic conditions.
2. The critical traffic management issue is the high volume of slow-moving construction vehicles on the causeway.
a. Unless and until the large volume of slow-moving causeway traffic is alleviated, much of which is due to construction trade and other hurricane recovery vehicles, a roundabout will experience the same intersection blockage and intersection gridlock that occurs today with the use of traffic control officers.
b. In short, a roundabout is not the answer, as it does nothing to address causeway traffic congestion.
3. An alternative solution.
a. A potential option to alleviate afternoon/early evening traffic congestion is to have causeway traffic on weekdays be two lanes in one direction for alternating periods of 10 to 15 minutes.
b. Causeway traffic, being two lanes in one direction for select intervals of time, is
i. A traffic management strategy that has the potential to move traffic off the island more efficiently and effectively than other traffic management options.
ii. An alternate solution that deserves thoughtful study under a complete TIA.
4. Causeway tollway booth lane reconfiguration.
a. The causeway tollbooth has three lanes for on-island traffic and one for off-island traffic.
b. In the days when each vehicle needed to stop to pay its toll to a tollway booth attendant, three lanes on-island and one lane off-island made perfect sense as a way to minimize tollbooth wait time for Sanibel bound traffic.
c. Transponder and pay-by plate are today’s only payment methods for the causeway toll.
d. When causeway reconstruction is complete, there will again be three on-island lanes. These lanes are obsolete and cause excessive back-ups in on-island traffic, as traffic goes from two roadway lanes to three toll booth lanes to one causeway lane.
e. Reconfiguring the causeway tollbooth lanes as two on-island and two off-island lanes is an immediate and cost-effective way to help decrease traffic congestion caused by causeway traffic slowdowns/back-ups.
5. Decision-making process/additional information needed: City council needs additional information to make an informed decision on the merits of a small roundabout.
a. The data from the ICE and VSSIM results is very limited and generic, and does not evaluate the traffic impacts of a small roundabout at Causeway Boulevard/Periwinkle Way.
b. City council has not received a proper Transportation Impact Analysis (TIA), a standard operating procedure.
c. A proper TIA will evaluate whether a small roundabout will alleviate or increase traffic congestion at the Causeway Boulevard/Periwinkle Way intersection and other key intersections.
d. Very importantly, there is no data/analysis on the impact of traffic congestion from:
i. Roundabout blockage due to eastbound Periwinkle Way traffic exiting the island on weekday afternoons/early evenings
ii. Roundabout gridlock from the northeast Causeway Boulevard merge lane and causeway traffic back-ups.
e. Kimley-Horn should provide the city with at least five examples of existing small roundabouts in other parts of the country that handle high volume traffic and are the same size as the proposed roundabout. This information should detail how the small roundabouts work in peak hour high volume traffic conditions with wait time data for all roundabout traffic movements.
f. Kimley-Horn should provide a complete traffic impact analysis for one-way causeway traffic at select time intervals.
6. Cost/economics and disruption.
a. The roundabout cost is estimated at $3.5 million to $5 million.
b. Using a mid-point roundabout cost of $4.25 million and assuming a $250,000 savings to the city in annual traffic control officer expenses, and ignoring borrowing costs, the roundabout has a 17-year pay-back, a very poor return on taxpayer dollars.
c. Suppose the issue is city expense for traffic control officers. In that case, the city should work with Lee County to institute a permanent causeway toll surcharge that covers the city’s annual cost for traffic control officers.
d. The construction of a new roundabout is very disruptive and will increase traffic congestion, an inconvenience that will further negatively impact residents, visitors, and businesses.
7. Traffic control officer safety.
a. We are all grateful and very appreciative of the outstanding work performed by the city of Sanibel traffic controls officers.
b. Traffic control officers work in all types of weather and traffic conditions, and by standing in the middle of a very busy intersection, they do so at considerable risk to their safety.
c. Constructing an elevated traffic officer platform in the middle of the Periwinkle Way and Causeway Boulevard intersection will improve traffic officer safety.
d. The intersection would be widened to accommodate a concrete and steel traffic officer platform four to six feet in height, large enough to allow the officer freedom of movement to direct traffic from all directions.
e. The scale and aesthetics of the traffic officer platform can be designed to be responsive to and respectful of the Sanibel Plan.
SECTION III: REQUESTED ACTION
I respectfully request that city council and city staff take the following action.
1. Delay approval of the $150,000 expenditure on the Kimley-Horn 30% Roundabout Design Authorization until city council receives the following information.
a. A full and complete traffic impact analysis for the proposed roundabout, using standard traffic analysis tools and real-world examples, in order to determine if a roundabout alleviates or increases traffic congestion.
b. A full and complete traffic impact analysis for the option of having causeway weekday afternoon/early evening traffic be two lanes in one direction for alternating periods of 10 to 15 minutes. Since the Causeway Bridge is a Lee County road, this analysis is an essential first step for this potential cooperative solution to afternoon/early evening traffic congestion.
c. An evaluation for constructing an elevated traffic officer podium for the Causeway Boulevard/Periwinkle Way intersection.
2. Work with Lee County officials to:
a. Reconfigure causeway tollbooth lanes to two on-island lanes and two off-island lanes.
b. Evaluate instituting a permanent causeway toll surcharge that covers the city’s annual cost for traffic control officers.
Thank you for your time, consideration, and hard work on behalf of all Sanibel residents, businesspeople, and visitors.
Don Hunter
Sanibel