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Roundabout Practices (2016)

Chapter: Appendix A - Summary of Statewide Roundabout Policies

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Page 38
Suggested Citation:"Appendix A - Summary of Statewide Roundabout Policies." National Academies of Sciences, Engineering, and Medicine. 2016. Roundabout Practices. Washington, DC: The National Academies Press. doi: 10.17226/23477.
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Page 39
Suggested Citation:"Appendix A - Summary of Statewide Roundabout Policies." National Academies of Sciences, Engineering, and Medicine. 2016. Roundabout Practices. Washington, DC: The National Academies Press. doi: 10.17226/23477.
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Page 39
Page 40
Suggested Citation:"Appendix A - Summary of Statewide Roundabout Policies." National Academies of Sciences, Engineering, and Medicine. 2016. Roundabout Practices. Washington, DC: The National Academies Press. doi: 10.17226/23477.
×
Page 40
Page 41
Suggested Citation:"Appendix A - Summary of Statewide Roundabout Policies." National Academies of Sciences, Engineering, and Medicine. 2016. Roundabout Practices. Washington, DC: The National Academies Press. doi: 10.17226/23477.
×
Page 41
Page 42
Suggested Citation:"Appendix A - Summary of Statewide Roundabout Policies." National Academies of Sciences, Engineering, and Medicine. 2016. Roundabout Practices. Washington, DC: The National Academies Press. doi: 10.17226/23477.
×
Page 42

Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

38 APPENDIX A Summary of Statewide Roundabout Policies State Policy Type Policy Text Policy Source Alabama None N/A N/A Alaska Preferred “Roundabout First” policy. Requires designers to provide a written justification of any decision to install a traffic signal instead of a single lane roundabout. Alaska DOT&PF roundabout website (52) Arizona Allow After ADOT assesses the input from the first two items above, ADOT staff will then determine whether or not to "consider" roundabouts. ADOT roundabout website (53) Arkansas Allow Implement… roundabouts, as appropriate. Arkansas’ Strategic Highway Safety Plan (54) California Evaluate Proposals to employ full control at state highway intersections (i.e. to control all approaching traffic via us of signal, stop or yield control) must consider all three intersection control strategies and the supporting design configurations during the ICE screening process. Traffic Operations Policy Directive (TOPD) 13-02 (45) Colorado Encourage Inferred N/A Connecticut Encourage Those locations which meet or nearly meet [signal] warrants, should be given consideration for roundabout installation. Intersections that are, or proposed to be, all-way stop controlled may also be good candidate locations for a roundabout Use of Roundabouts on State Highways Memorandum (55) Delaware Encourage The potential benefits of reductions in injuries and costs associated with crashes are sufficient alone to recommend modern roundabouts as a first option when safety, capacity, or traffic calming are chief reasons for intersection projects Delaware Department of Transportation Guidelines on Roundabouts (56) District of Columbia Allow Inferred N/A Florida Evaluate Roundabouts shall be evaluated on new construction, reconstruction and safety improvement projects, as well as anytime there are proposed changes in intersection control that will be more restrictive than the existing conditions. Florida Roundabout Guide (57) Georgia Evaluate Roundabouts are the preferred safety and operational alternative for a wide range of intersections of public roads. A roundabout shall be considered as an alternative in the following instances: (1) Any intersection in a project that is being designed as new or is being reconstructed. (2) All existing intersections that have been identified as needing major safety or operational improvements. (3) All signal requests at intersections (provide justification in the Traffic Engineering Study if a roundabout is not selected). Modern Roundabouts in Georgia (58) Hawaii Encourage [Roundabouts] should be considered as alternatives to stop lights and stop signs News Article (59) Idaho None None N/A Illinois Encourage Roundabouts [should] be considered as an alternative intersection during all intersection improvements. Illinois Center for Transportation: Roundabout Evaluation and Design: A Site Selection Procedure (60)

39 State Policy Type Policy Text Policy Source Indiana Encourage A roundabout should be considered as one potential intersection option within an INDOT-sponsored or -funded planning study or project since it offers improved safety, cost savings, and enhanced traffic operations. This includes a proposed freeway interchange where an at-grade intersection currently exists or will be created at the ramp terminals. A comparison of roundabout practicality or feasibility versus other intersection types should be conducted, considering safety, traffic operations, capacity, right- of-way impacts, and cost. Other factors as described below can also be included in the evaluation if desired and deemed appropriate. In conducting such comparisons, a roundabout is not always the optimal solution, but it can often offer significant benefits. The Indiana Design Manual (61) Iowa Encourage The Iowa Department of Transportation and other communities in Iowa have started using roundabouts in certain situations to enhance safety and reduce delays encountered by the motoring public. Iowa Comprehensive Highway Safety Plan (CHSP) (62) Kansas Encourage While KDOT does not have a formal policy at this time dictating the use of roundabouts, KDOT prefers that roundabouts be considered as an intersection alternative for potential operations and safety improvements. Kansas Roundabout Guide (63) Kentucky Allow A modern roundabout is an alternative form of intersection control to traffic signals and multi-way stop control intersections. Therefore, roundabouts may be considered only when these intersection control types are warranted. Highway Design: INTERSECTION—At Grade Intersections: Modern Roundabouts (64) Louisiana Allow Roundabout shall be justified by a benefit cost safety analysis or a capacity analysis comparison. There must be sound engineering reason to justify the installation of a roundabout. EDSM VI.1.1.5— Roundabout Safety and Approval (65) Maine Allow MaineDOT will generally allow implementation of a roundabout provided that over a 20-year design life, basic safety standards are met and the roundabout performs equal to or better than the no build alternative. In the event that mobility is reduced compared to the no build alternative, MaineDOT will consider whether reduced mobility is part of the Purpose and Need along with posted speed limits, Highway Corridor Priorities and Customer Service Levels. Maine DOT Roundabout Analysis Requirements (66) Maryland Evaluate SHA has adopted a policy that roundabouts will be considered at all intersections where improvements are being considered. Maryland Roundabout Program: Early Years and Program Growth (67) Massachusetts Encourage Roundabouts can be appropriate design alternative to both stop-controlled and signal-controlled intersections. … At higher combinations of major street and minor street volume, traffic signals become the common traffic control measure. Roundabouts should also be considered in these situations. Massachusetts Highway Design Guide (68) Michigan Encourage Roundabouts should be considered as one potential intersection option within MDOT-sponsored or funded planning studies/design projects since they offer improved safety, cost savings, and enhanced traffic operations in many situations. MDOT Roundabout Guidance Document (69)

40 State Policy Type Policy Text Policy Source Minnesota Evaluate In general terms, any intersection—whether in an urban or rural environment—that meets the criteria for additional traffic control beyond a thru stop condition, also qualifies for evaluation as a modern roundabout. Therefore, in any planning process for an intersection improvement where a traffic signal or a 4-way stop is under consideration, a modern roundabout should likewise receive serious consideration. Additionally, roundabouts should always be considered as an improvement strategy for existing 4-way stop or signal- controlled intersections with safety or operational problems. MnDOT Road Design Manual: Chapter 12: Design Guidelines for Modern Roundabouts (70) Mississippi None N/A N/A Missouri Allow The process of selecting a roundabout as the preferred form of traffic control for a given intersection has three stages. If a roundabout is not “preferred” at any one of these stages, it will cease to be considered as a viable form of traffic control at the given location. MoDOT Engineering Policy Guide (71) Montana Encourage Roundabouts are installed at selected state roadway intersections to improve safety and mobility. MDT Roundabouts Website (72) Nebraska Allow The Traffic Engineering Division conducts an engineering study to evaluate the operation of an intersection and to determine the appropriate traffic control to be provided. Nebraska Department of Roads: Roundabouts (73) Nevada Encourage In a continual effort to provide the safest roadways, the Nevada Department of Transportation installs roundabouts at selected State roadway intersections to improve safety and mobility. Nevada DOT Roundabout Website (74) New Hampshire Evaluate Roundabouts can be placed at an intersection under any type of operational control. Due to the improved safety, operation and capacity benefits of roundabouts it shall be standard procedure at the NH DOT to evaluate any intersection considering signal control to see if a roundabout would be beneficial. NH DOT Supplemental Design Criteria (75) New Jersey Allow A roundabout is a circular, raised traffic island placed within the intersection of two or more streets. It operates on the “yield-on-entry” principle. Drivers circumnavigate the island in a counter-clockwise direction. Roundabouts limit speeds by horizontally deflecting vehicles as they pass through an intersection. They reduce crashes by separating movements and reducing speeds. NJDOT Roadway Design Manual, Section 15 Traffic Calming (76) New Mexico Allow Inferred New Mexico Department of Transportation— Driving in Roundabouts (77) New York Preferred When the analysis shows that a roundabout is a feasible alternative, it should be considered the Department’s preferred alternative due to the proven substantial safety benefits and other operational benefits. Highway Design Manual (78) North Carolina Encourage The choice of using a roundabout is made on a case- by-case basis. NCDOT evaluates traffic volumes and crashes at each candidate intersection individually to determine if a roundabout would be the most effective solution. Traffic Engineering: Policies, Practices and Legal Authority Resources (79) North Dakota None N/A N/A

41 State Policy Type Policy Text Policy Source Oklahoma None N/A N/A Oregon Encourage Asks everyone to give serious consideration to intersection control alternatives beyond merely traffic signals. Intersection Control Using Roundabouts (81) Pennsylvania Encourage When planning for intersection improvements, a variety of improvement alternatives should be evaluated, in addition to roundabouts, to determine whether a roundabout is the most appropriate alternative. Pennsylvania Guide to Roundabouts (82) Rhode Island Preferred Using modern roundabouts in place of traditional intersections is a safer solution we're looking to employ wherever we can. Roundabouts for Rhode Island (83) South Carolina Encourage Use of roundabouts is recommended at locations with major safety or operational issues where the higher costs for the construction can be justified by the crash reduction or operational improvements. Charting a Course to 2040; Multimodal Transportation Plan; Safety and Security (84) South Dakota None The South Dakota Strategic Highway Safety Plan (pp. 29–31) provides information on intersection crashes and proposals for several types of improvements and preventative measures to reduce crashes, injuries and fatalities - including roundabouts. South Dakota DOT Roundabouts website (85) Tennessee Allow Inferred Instructional Bulletin No. 10-07 (86) Texas Allow Roundabouts can be appropriately implemented in Texas Texas Roundabout Guidelines Final Report (87) Utah Encourage Inferred Developing Guidelines for Roundabouts (88) Vermont Preferred The general assembly finds that the installation of roundabouts at dangerous intersections in the state has been cost-efficient, and has enhanced the safe operation of vehicles at these locations. The agency of transportation is directed to carefully examine and pursue the opportunities for construction of roundabouts at intersections determined to pose safety hazards for motorists. Vermont Legislature (89) Virginia Preferred VDOT recognizes that Roundabouts are frequently able to address the above safety and operational objectives better than other types of intersections in both urban and rural environments and on high-speed and low-speed highways. Therefore, it is VDOT policy that Roundabouts be considered when a project includes reconstructing or constructing new intersection(s), signalized or unsignalized. The Engineer shall provide an analysis of each intersection to determine if a Roundabout is a feasible alternative based on site constraints, including right of way, environmental factors and other design constraints. The advantages and disadvantages of constructing a Roundabout shall be documented for each intersection. When the analysis shows that a Roundabout is a feasible alternative, it should be considered the Department’s preferred alternative due to the proven substantial safety and operational benefits. Road Design Manual (90) Ohio Encourage Roundabouts can be placed at an intersection under any type of operational control. Due to improved safety, operation and capacity benefits of roundabouts, a roundabout may be evaluated at any intersection considering signal control to see if a roundabout would be beneficial. Design Manual (80)

42 State Policy Type Policy Text Policy Source Wisconsin Evaluate If an intersection warrants a signal or a four-way stop within the design life of the proposed project, the modern roundabout shall be evaluated as an equal alternative. Where there is an existing four-way stop or signal and there are operational problems with the current control, then the roundabout shall be considered as a viable alternative. As stated above the roundabout may be a viable alternative for a two-way stop control in certain circumstances. In either case, roundabouts are a potential intersection control strategy until such time that the evaluation indicates that the roundabout alternative is not appropriate. Roundabout Guide (92) Wyoming None N/A N/A Washington Evaluate If warrants are met, evaluate multi-way stop, roundabout, and signal. If warrants are not met, evaluate yield, two-way stop, multi-way stop, and roundabout. Design Manual (91) West Virginia None N/A N/A

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TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 488: Roundabout Practices summarizes roundabout policies, guidance, and practices within state departments of transportation (DOTs) as of 2015. The synthesis may be used as a reference for state agencies that are creating or updating their roundabout and intersection control policies.

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