Note: Close Pass threat sets up doorings

Squeezed by passing vehicles cyclists are forced into door zone danger.  Close Pass measures address the real risks of being hit or rear-ended by motorists, and increase acceptance of cyclists' right to the road.  Ultrasound systems deployed by police bike safety details make such laws work and road sharing will improve.


Dear Shane Ross, Minister for Transport, Tourism and Sport
I wish to share information in response to the 5 Jan 2018 Irish Times* article which reports that you have expressed concern about the enforceability of 'close pass' legislation.
Please note that a working technology exists and has been productively deployed for several years now by the Police Dept of Chattanooga, Tennessee, USA. Their practice is now being emulated elsewhere in the USA. It is now promoted by the US Governors Highway Safety Association (GHSA) in its most recent and extensive research report on bicycle safety where it appears as one of 30 highlighted recommendations:
A Tool to Help Officers Enforce Safe Passing Laws - on page 39 of 
A Right to the Road - Understanding & Addressing Bicyclist Safety
This bike-mounted assemblage of devices has at its core an ultrasound unit to measure distance. It is used by officers to document drivers' passing range -- much as road radar is used to gather measurements to enforce posted limits & deter speeders. 
A specific description of the system (which costs about $1500 US.) is provided here:  
A news article describes its introduction here:
Close Pass Policing with GoPro & ultrasound
3 feet or else: Chattanooga police use ultrasound technology to enforce law for cyclist safety

You may find a labeled photo of the set attached below or find it as slide #15 of the webinar slide set which accompanied the roll-out of the GHSA report.  Those slides are linked for download at:

GHSA Press Release >> recorded Webinar > Download Webinar Slides 
I expect you can learn more by about Chattanooga's use of the system by contacting the Chattanooga Police Dept. directly , &/or requesting the following documents: 
Chattanooga Police Department. (2015). Law
enforcement guide, Enforcing bicycle traffic
laws. Chattanooga, TN.

Chattanooga Police Department. (2016).
CHA-SBI: Chattanooga safe biking initiative
[Report]. Chattanooga, TN.

Should your road safety experts already have familiarity with such systems and have substantial reservations about such methodologies, I would most appreciate receiving a copy of their findings.

But if the above is new information I hope it proves a useful contribution to your deliberations.

Yours truly,
Michael Charney
Michael Charney, MD (retired)
Dutch Reach Project
Cambridge, MA, USA
dutchreachorg //a/t-// 
 * Shane Ross raises doubts over new law to protect cyclists
Minister’s foresees problems, asking: ‘How do you prove someone is 1.5 metres away?’
The Physics Package™ C3FT™ is a bicycle-mounted electronic system designed for the purpose of detecting, capturing, and displaying the proximity of passing vehicles. It is compatible with most typical bicycle configurations and no special equipment is needed.

Primarily designed for law enforcement and municipalities which have or are considering safe bicycle passing laws, its accurate distance measurement can serve as the basis for driver education or citation activities. It also provides a new and powerful capability for roadway safety surveying and infrastructure planning.

C3FT™ uses a sensitive ultrasonic detector on an adjustable arm to provide a fast, reliable distance measurement on a high-brightness numeric display. Buzzer and LED indicators alert the user when a passing vehicle triggers a preset distance threshold. An external device is required for data recording and the system includes an adjustable mount for an optional video camera to document the distance display, facility layout, and traffic activity.

System Features:

  • High-Brightness LED Numeric Display designed for visibility in direct sunlight

  • Inch and Centimeter Settings for both measurement display and trigger threshold distance

  • User Configurable Threshold Setting enabling custom distance triggers for alarm buzzer and LED indicators

  • Continuous Mode displays continuous real-time distance measurement

  • Capture Mode captures and displays nearest measurement inside threshold, reset by front-panel button

  • Single Unit Device and Toolless Install for simple and fast deployment

  • Right- or Left-Facing Orientation Support for both right-hand traffic (RHT) and left-hand traffic (LHT) countries as well as one-way roads with left or right-passing situations

  • Handsfree Use enabling ease of operation and user interaction after pass events

  • Rated IP67 against dust and liquid intrusion

  • Lithium-ion Battery Powered enabling long run time and simple recharging

  • Made in the USA and meets the requirements of the Buy American Act

The current generation of C3FT (see-three-feet) was introduced in July of 2017 and builds on the success of the v2 platform by integrating a range of usability and functionality improvements driven by 2 years of real-world use with feedback from US and International enforcement agencies, municipalities, and advocacy groups.

Version 3 was developed to meet the needs of law enforcement by providing an accurate and verifiable method to conduct education and enhanced enforcement activities related to Vulnerable User Laws, more commonly referred to as Safe Passing Laws. Like previous versions, it is also designed to be used for statistics gathering and research related to driver pass and post-pass behavior.

Consisting of a single integrated unit, C3FT v3 features toolless installation and removal to simplify deployment and make field adjustment possible. It is designed to deploy on any bike configuration or handlebar style without requiring modifications to the bicycle. The sensitive ultrasonic detector is mounted on an adjustable arm and provides fast, accurate, and reliable distance measurements which are displayed on a high-brightness numeric display. This measurement and the associated threshold setting is available in either inches (8 – 99) or centimeters (20 – 250) and is user configurable. An external device is required for data recording and the C3FT system includes an adjustable mount for an optional video camera to record the distance display, facility layout, and traffic activity.

Featuring a simplified interface, version 3 has been specifically designed to enable users to operate it with minimal training, enable passive monitoring with few distractions, and clear feedback and prompting during and after pass events. Buzzer and LED indicators alert the user when a vehicle passes within the user specified distance threshold. C3FT v3 has been reconfigured to enable handsfree use so that controls are operable without requiring the user to lift his or her hand from the handlebars during and after a pass event alert has been registered.

Mounting and suggested alignment diagram for the C3FT v3 system.

Training officers to use the device and make intervention to inform & discourage close pass behavior has widening benefits.1) Officers will be educated & empowered to attend to bike safety road sharing issues.

2)  Public education will result from media reports (and controversy) about the system & its deployment; motorists will see officers patrolling with such devices and word of mouth will expand public awareness and induce behavior change.
3) It will enhance the prestige and bike safety motivation of bicycle police details, helping them become more aware themselves of Close Pass infractions, and lead direct more attention to drivers' road-not-sharing conduct. 
Photo of bicycle handle bar mounted detection and recording devices used by Chattanooga Police to deter and enforce close passing law to protect bicyclists from collision by motor vehicles operating illegally when passing within 3 feet.

Click image to enlarge. Photo of The Physics Package™ C3FT™ as found in GHSA slide set here:  .  It is also referenced and described on page 39 of the GHSA's 2017 report: A Tool to Help Officers Enforce Safe Passing Laws -
A Right to the Road - Understanding & Addressing Bicyclist Safety

Times Free Press: 3 feet or else: Chattanooga police use ultrasound technology to enforce law for cyclist safety

Irish Times: Transport Minister Expresses Doubt on Close Pass Enforcement

Bicycling advocates urge close pass legislation to protect cyclists from dangerous passing by motor vehicles, cars, trucks, buses, lorries, etc. Transport Minister Shane Ross reportedly expressed skepticism as to whether police could measure distance between cyclist and car or vehicle. Yet Chattanooga TN police have just such a system and it works!

Irish Times, 5 January 2018:
Transport Minister Shane Ross apparently unaware of existing technology to prove close pass by police.

Supplementary documentation (not included in letter above).

Labeled Photo of Bicycle Mounted Close Pass System

Technology to detect close pass violations by vehicles when used by police bicycle safety unit to enforce laws against dangerous passing by motorists.

Bicycle mounted close pass ultrasound system used for deterrence & enforcement which includes ultrasound sensor range finder device, Go Pro digital camera, Alarm Buzzer & digital distancecapture display. For more, go to Codaxus LLC Physics Package™ C3FT™ document here:
Photo source: Slide #15: . Photo credit:
Chattanooga [Tennesee, USA] Police Dept.

Diagram: Close Pass Monitoring System for Police Use

Diagram illustrates arrangement of parts for close pass detection and capture system on bicycle handlebars.

Diagram of Bbcycle mounted close pass ultrasound system used for deterrence & enforcement which includes ultrasound sensor range finder device, Go Pro digital camera, Alarm Buzzer & digital distancecapture display. For more, go to Codaxus LLC Physics Package™ C3FT™ document here:

Diagram & Photo Inset of Close Pass Ultrasound Device

Diagram of ultrasound unit accompanied by inset photo of Codaxus unit

Closs Pass Ultrasound Unit diagram with photo. Link to Codaxus LLC Physics Package™ C3FT™ specifications document: