A Human-Machine Model for Road Traffic Safety

In this brief article, we look at the issue of road safety with the help of a human-machine model. A safe road traffic system has a multitude of contributing factors. Let’s take a look at the Indian road traffic scenario in context of this model. Written by Srinath R, Manager, Program & Project Management at FGS Engineers & Innovators.

The Brasilia Declaration on Road Safety, 2015 aimed to halve the number of global deaths and injuries from road traffic accidents by 2020. India, being a signatory to the declaration, adopted numerous measures to bring down the number of road accident fatalities and injuries. Despite all the efforts, the number of road traffic crashes and related casualties remain high. To a fair extent, it can be said that the measures are not attaining fruition because they are not integrated but limited to individual domains. The Stockholm Declaration, 2020, reaffirmed the commitments of the Brasilia declaration to address the 1.3 million global deaths and tens of millions of injuries from road traffic crashes by 2030. If we are to realize that target, we need to look at the issue of road safety in all its dimensions and dynamics. The human-machine model can aid us in this problem.

If we consider a highway as a human-machine model, it would be as in the following figure.

Often, we hear that 1-1.5 lakh lives are lost on Indian roads every year from 3-5 lakh traffic incidents. In 2020 alone, 1,31,714 deaths were reported from 3,66,138 road accidents in India, although there was a considerable decline in the number of accidents (probably due to extended lockdowns across the country). Close to 3.5 lakh people were injured in these accidents. Close to 70% of all the fatalities in these accidents were aged 18-45. It is worth noting that not all road traffic accidents are reported to the State. There is probably no statistic regarding the number of cases going unrecorded every year. The Government of India, recently, had stated that India ranks first in terms of road accident fatalities and third in terms of the number of persons injured. According to latest reports, the declining trend in number of cases in 2020 seems to have reversed in 2021 itself.

For decades, every debate on the problem of road traffic safety has centered on one factor alone- roads. Such debates conveniently ignore other significant factors – the human, the vehicle and the environment. Instead of looking at the problem in silos, the human-machine model gives a holistic perspective to the issue at hand. Pedestrians and vehicle users, both interact with the environment. Their actions and reactions are influenced by the environment as well. It is a reciprocal relationship.

The Human Factor

Every system is supposed to be designed for the human who uses it or interacts with it. If we consider road traffic as a system, we should account for the possibility of error that a human can commit within the provisions of the system in its entirety. Rash and negligent driving is a major reason for road traffic crashes, according to the authorities. To a great extent, this kind of driving/riding arises from one’s undue confidence in his own skills and belief in the abilities of the vehicle used.

The Machine Factor

Over the past few years, there have been remarkable technological advances in the field of automotives. From vehicles that struggled to cross 60kmph, we now have cars and bikes that go from 0-100kmph in a few seconds. As part of these developments came a few safety-related technologies such as seat belts, air bags, ABS, EBD, and so on. In addition, development of infotainment systems has gone ahead so much that a vehicle can be used as a mini-home or mini-office. A limited study done by this author back in 2015 had estimated that over 75% of four-wheeler drivers tend to use mobile phones while driving. This has only got worse in the following years with the advent of hands-free technology. The question of safety arises when the people interacting with these automotive systems go on to mix up their purposes. The interaction of humans with these systems and their subsequent effects on driving and safety are yet to be clearly understood.

The Environment Factor

This is perhaps the most unpredictable factor in the human-machine system. There is a continuous give and take relationship between drivers and their environment. For two-wheelers, the environmental interaction is mostly external, whereas for bigger vehicles, there are both internal and external interactions. It is reasonable to assume that the external environment has larger dynamics. From an Indian driver's perspective, pedestrians, presence of heterogenous traffic and sporadic movements in such traffic, weather conditions, quality of roads, external distractions, etc. often determine the level of safety on the road. The higher the unpredictability from the environment, the higher the probability of road traffic crashes.

Looking at the issue of road traffic safety through the lens of the human-machine model helps to determine countermeasures comprehensively. Just as the problem has multiple dimensions, there are many dimensions to the solution as well. The model makes sure that the problem is understood in a better and holistic way, and pragmatic solutions addressing each factor is found.