Is A New Roundabout Coming to Troy?
Consultants recommend a new roundabout at one of the city's busiest intersections
City Council will meet as a Committee of the Whole on Monday, September 11th to discuss installing a new roundabout at the intersection of West Main Street and South Stanfield/Experiment Farm Road on the City’s west side. This announcement not only shares the details of the meeting, but also has a link to the study by American Structurepoint that recommends the move to put in a roundabout.
This comes at a time where the city has installed a new roundabout at the intersection of Dorset Road and McKaig Avenue and has designs to put in a new roundabout at North Adams Street and Staunton Road/Riverside Drive; both intersections were mulitple lane four-way stop intersections. The installation of a new roundabout at West Main Street and South Stanfield/Experiment Farm Road will be the first time a signalized intersection is proposed for a roundabout.
American Structurepoint’s report provides a detailed analysis of traffic conditions and recommends the installation of a roundabout at one of the most busiest intersections in the community. This edition of the Civic Capacity newsletter will dive into the report's methodology, findings, and recommendations, focusing on the rationale for choosing the roundabout as the preferred option.
Methodology and Data: The report employs a rigorous methodology to evaluate traffic conditions and intersection performance. The use of established software and LOS criteria from the Highway Capacity Manual lends a great deal credibility to the analysis that is provided. However, the report lacks information on traffic data sources, which is essential for transparency and replicability, though current data relies on traffic counts that the consultant provided.
The consultants readily admit that the intersection works well for the time being; using the Level of Service (LOS) data that was gathered, all parts of the intersection, both in the morning and afternoon drive times show that the intersection is operating at a C Level of Service.
The report assumes that the construction of the roundabout will begin in 2024 (pg. 8) and makes forecasts in traffic in 2047, twenty three years after the construction of the road. The study also assumes that traffic will grow at the intersection at a flat rate of 1% per year over the twenty-three year period.
The methodology also does to not provide any discussion on pedestrian and bicycle usage. It should be noted that the city does have an adopted complete street policy, in which this analysis did not discuss and the recent improvements on South Stanfield Road, made significant pedestrian and bicycle infrastructure improvements. The report also did not appear to take in any data on traffic accidents or traffic citations at the studied location; it would appear that the intersection is working well under the current loads of traffic.
LOS Criteria and Thresholds: The report relies on Level of Service (LOS) criteria to assess intersection performance, which is a common industry practice. The thresholds for LOS are clearly defined in the report, making it easy for readers to understand the evaluation criteria. However, the report does not explain why these specific thresholds were chosen, and whether they align with local or national standards.
Scenario Analysis: American Structurepoint’s report presents three scenarios: No Build, Traffic Signal Improvements, and Roundabout. Scenario 1 (No Build) provides a baseline for comparison. Scenario 2 (Traffic Signal Improvements) and Scenario 3 (Roundabout) represent potential solutions to address traffic issues. This comprehensive approach allows for a thorough examination of alternatives that are presented.
Scenario 1 - No Build: The analysis of this first scenario highlights existing and future traffic issues, emphasizing the need for improvements. However, the report could benefit from a more detailed explanation of why LOS deteriorates over time and what factors contribute to the observed congestion. Additionally, the report fails to discuss the potential environmental and safety implications of not addressing the traffic issues. Personally, what I found interesting in the capacity analysis results of this scenario is that the delay fitgure presented increased modestly (from 20 seconds to 25 seconds) in the morning data from 2023 to 2047. However, the increase is most notably in the afternoon data over the same time (from 25 seconds to 123 seconds). Regardless of the assumptions in the data, it does appear that some improvements are warranted at the intersection, but the question is when are those improvements warranted? It is clear to see from the forecasting that the intersection will be problematic by 2047, but it is not clear from the data at what year the intersection will begin to be problematic.
Scenario 2 - Traffic Signal Improvements: The second scenario focuses on implementing a traffic signal and associated improvements. The analysis results show that the proposed signal is expected to operate at an overall Level of Service of C. While the report provides a conceptual layout and cost estimates, it lacks a thorough discussion of potential drawbacks, such as increased wait times at red lights and the possibility of rear-end collisions, which are common issues associated with traffic signals.
Scenario 3 - Roundabout: The final and recommended scenario evaluates the installation of a roundabout. The report finds that the roundabout is expected to operate at a Level of Service of C for the afternoon drive and a Level of Service of A for the morning drive. The analysis includes a detailed description of the roundabout's design, which is essential for understanding its potential effectiveness. However, the report does not discuss potential challenges related to driver behavior, such as navigating multi-lane roundabouts, or the need for public education regarding roundabout usage.
Cost Estimates: The report provides cost estimates for both scenarios, highlighting that the cost difference between the traffic signal and roundabout alternatives is negligible. The cost for the new signal installation (Scenario 2) is estimated to be $3.6 Million and the cost for a new roundabout (Scenario 3) is estimated to be $4.2 Million. As the community analyzes this potential project, it would be beneficial to include a discussion of long-term maintenance costs and potential cost savings associated with the chosen option; in addition, a discussion of potential external funding sources may lessen the burden on individual taxpayers depending on the option chosen.
Recommendations: The report recommends Scenario 3, the installation of a roundabout, based on capacity analysis results. While the rationale for this recommendation is clear, the report lacks a detailed discussion of the broader benefits of roundabouts, such as improved safety, reduced fuel consumption, and potential environmental benefits. Additionally, a brief risk assessment of the roundabout option could provide a more comprehensive view of its viability.
The report offers a well-structured analysis of traffic conditions and intersection performance, ultimately recommending the installation of a roundabout. But even that recommendation seems tepid when analyzed, the extra $600,000 in up front expense won’t improve the afternoon drive, but it will make the morning drive better.
The report could also benefit from more transparency regarding data sources, a deeper exploration of the implications of each scenario, a deeper discussion of the assumptions made of traffic growth between 2023 and 2047 and a more comprehensive discussion of the chosen option's benefits and potential challenges. Nonetheless, the report serves as a valuable starting point for the entire community when analyzing the options for this intersection.
This is a community decision and community input is needed. Again, it is important to note that City Council will have a discussion on this roundabout on Monday, September 11th at 6:00 p.m. in Council Chambers. The public is more than invited to attend. You can also feel free to answer the poll question below and leave your thoughts in the comment section.
Roundabout are a very economical and safe way to manage traffic congestion. I much prefer this solution to sitting and wasting gas at a red light particularly when there is no cross traffic. Also noting that this intersection is at an an odd angle, not 90 degrees, which the proposed solution addresses better than a traffic light.
Thanks for sharing this information. I came across information a couple weeks ago that talked about these roundabouts a couple weeks ago and how it was done during WW2 by Hitler. I tried to find it again to share . If I find it again I will share it as it was a PDF full of information. It maybe in the Library of Congress.