All posts by Mark Johnson

Best Paper Award at 2018 TRB Annual Meeting!

Mark Johnson receiving award at TRB.

Mark T. Johnson and Ting-Li Lin’s (Ph.D., Statistics) paper, “The Impact of Geometric Factors on the Capacity of Single-Lane Roundabouts,” received the TRB Roundabout Committee’s Best Paper Award, presented at the 2018 TRB Annual Meeting in Washington, DC. The paper will be published in the 2018 Transportation Research Record (TRR), Journal of the Transportation Research Board.

The paper compared two methods of capacity estimation on US Data — HCM6 gap-acceptance and Kimber’s geometric model. Our statistical analysis showed that the geometric model was more accurate, and produced better predictions than HCM6 model. See the full paper here and watch the paper presentation below.

MTJ to Present Paper at TRB Annual Meeting

Mark Johnson, PE will be giving three presentations at the 2018 TRB Annual Meeting in Washington, DC.

Jan. 9, 10:15am – 3:15pm – Roundabout Video Theater
1) Morning session: Video presentation – “Roundabout Design & Traffic Planning for All Modes

2) Afternoon session: Case Study presentation – “Innovative Pedestrian/Bike Design Treatments in an Urban Compact Roundabout

Jan. 9, 3:45pm – 5:30pm – Podium Presentation
3) Mark will present his paper, “The Impact of Geometric Factors on the Capacity of Single-Lane Roundabouts,” which was accepted for publication.

Co-authored with Ting-Li Lin, Ph.D., the paper compared two methods of capacity estimation – HCM gap acceptance and Kimber/Hollis’ geometric model. Our statistical analysis indicated that the geometric capacity model was more accurate.  The uncalibrated geometric capacity model produced better predictions than the calibrated HCM6 model.  This paper concluded that the accuracy of capacity prediction is improved by including geometric variation, and the geometric differences between roundabout sites were the primary cause of the differences in driver behavior at those sites.

Mark Johnson Presenting at OTEC

OTEC logoMark Johnson, PE will be presenting at the Ohio Transportation Engineering Conference in Columbus, OH. His presentation “Too Many Crashes at Your Multi-Lane Roundabouts? Learn How to Optimize Safety for Multi-Lane Roundabouts” will be on Oct. 11 at 8am.

Session 49 – More About Roundabouts
Room: A110-112

Multi-lane roundabouts are having excessive PDO or minor crashes, which is creating many challenges for implementation. This presentation details the essential components for designing optimal roundabout safety and operations, and highlights how these elements blend together that affects how drivers process that information and then react to it.

See you there at this topical presentation!


Mark Johnson Presenting at TRB Webinar

Mark Johnson will be presenting at the TRB webinar “Modern Roundabouts: Downtown and Suburban Revitalization.

The webinar will be on Monday, September 18, 2017, from 2:00 PM to 4:00 PM ET and will provide examples of ways the modern roundabout may be able to revitalize a downtown area, enhance a community’s sense of place, and provide a safer and more efficient traffic flow in urban and suburban areas. Presenters will describe how roundabouts have jumpstarted downtown revitalization, illustrate how roundabouts have enhanced communities, and demonstrate how roundabouts have improved traffic flow.

Two PDH credits are available. For more information or to register see TRB’s webinar page.

Breckenridge, CO Roundabout Now Open

The first roundabout on the Park Ave. Corridor in the Town of Breckenridge, CO is now open! The roundabout at 4 O’Clock Road and Park Avenue held its opening ceremony on June 30, 2017. 

This is the first roundabout planned along a corridor of nine roundabouts on Park Avenue (SH 9). MTJ Roundabout Engineering worked with the Town of Breckenridge, CO and McDowell Engineering on the peer review for this project.



MTJ to Present at ITE/CITE 2017 Annual Meeting

Mark T. Johnson will present during the ITE/CITE 2017 Annual Meeting and Exhibit on July 30 -Aug. 2 in Toronto, Ontario. The poster session on July 31, 3:30-4:30 in Exhibit Hall will include our poster “Solving Complex Issues with Innovative Roundabout Applications.” Several complex roundabout applications will be discussed including the closely spaced roundabouts at STH 83 / USH 18 and Blackwood Dr. / USH 18 in Wales, Waukesha County, WI.

Olympic Blvd. Roundabout Opens in Lafayette, CA

Pleasant Hill and Olympic Blvd., Lafayette CA

The first roundabout in Lafayette, CA is now open at Pleasant Hill and Olympic Blvd.!
MTJ provided capacity analysis and final horizontal design, signing, marking, and ped/bike facilitation design for this roundabout. High levels of design alternatives and communication were involved with the City’s Ped/Bike Commission to address design questions and reach consensus on pedestrian and bicycle mobility and safety. Consensus was attained through design alternative development and thorough explanation and discussion about relative benefits of various design treatments. Project partner was Omni-Means.