100 Years of the Ubiquitous Traffic Lights: An All-Round Review

Abstract

Three-colour four-way traffic light completed 100 years in 2020. Even though the traffic light in the form of Semaphore arms has been in use in London since 1868, electric traffic lights came into existence in 1912 and the standard three-colour four-way light in 1920. Research is continuously being carried out to develop better algorithms to improve safety, reduce travel delays, and optimize road capacity. Hence a review of the evolution of traffic lights is warranted. This paper presents an all-round review using a six-prong approach. Timeline of the evolution of the literature in the last 100 years, the evolution of hardware, algorithms, traffic control schemes, standards and the pedestrian lights and count down timer are the six areas in which the review is carried out. A timeline of the different keywords related to the various algorithms in use is presented. This article delves into the thinking and meticulous approach of early researchers and practitioners of the field while dwelling on the past. They laid the rock-solid foundation of today’s research. Also, future research areas like connected vehicles and automated vehicles are pointed out, and a summary of the findings is presented at the end.

KEYWORDS:

• Traffic Lights
• Algorithms
• Traffic Control Schemes
• Traffic Standards
• Evolution

ACKNOWLEDGEMENT

The first author wishes to acknowledge the help rendered by Librarian Sh. R. K. Shukla and Assistant Librarian Dr. Lalita for making available many referred old manuscripts from various databases during the CoVid2019 pandemic remotely.

DISCLOSURE STATEMENT

No potential conflict of interest was reported by the author(s).

Additional information

Notes on contributors

Ashish R. Kulkarni

Ashish R Kulkarni received BE from Govt Engineering College, Aurangabad, ME from COEP in 2002. He worked in KIET, Muradnagar, Ghaziabad, India from July 2000 to Oct. 2003. He then worked in MTNL, Delhi as JTO (Project CDMA), JTO (CC and BCCS), assistant manager (RCMS and CC), and GSM. He joined DTU in Dec 2009 as an assistant professor in the Department of Electrical Engineering. His research areas are intelligent transport systems, control systems, embedded systems, microcontroller-based products, and electric vehicles.

Narendra Kumar

Narendra Kumar has done BE from IIT-Roorkee in 1985, ME from PEC Chandigarh in 1987 and PhD from Delhi College of Engineering (Now known as Delhi Technological University), Delhi in 2003 in electrical engineering. He is currently a professor (on lien) with the Department of Electrical Engineering, Delhi Technological University, Delhi, India. He is currently serving as campus director, NSUT East Campus, Delhi. His current area of interest is power electronics applications in power systems, instrumentation and control. He has published more than 100 papers. E-mail: [email protected]

K. Ramachandra Rao

K Ramachandra Rao is a professor and an MoUD chair in civil engineering and a joint faculty in the Transportation Research and Injury Prevention Centre (TRIPC) at the Indian Institute of Technology (IIT) Delhi. His main research interests are traffic dynamics – pedestrians and vehicles, public transit planning, road safety, and urban freight logistics. E-mail: [email protected]