Remote Sensing: Smart policing of emissions on-road

India needs smarter and effective policing of emissions on road to reduce public health risk

By Anumita Roychowdhury
Last Updated: Monday 14 May 2018

Worldwide, remote sensing is used for two regulatory approaches—“dirty screening” and “clean screening”Not many have noticed this notable directive from the Supreme Court on May 10, 2018. Responding to the recommendations from the Environment Pollution and Prevention Control (EPCA), it has instructed the Delhi government to look into the implementation of remote sensing technology for screening of polluting vehicles on-road. This was among the recommendations of EPCA in response to an earlier Supreme Court order of March 23, 2018, that had asked to examine the new parameters that could help to improve the current vehicle inspection system, Pollution Under Control Certificate (PUC). If implemented, remote sensing can dramatically alter the way we monitor emissions from on-road vehicles and allow more efficient screening of highly polluting vehicles.

Smart monitoring of on-road emissions has become necessary and inevitable in Delhi as most of our on-road fleet has become BS-IV compliant and we are poised to leap to a more sophisticated genre of Bharat Stage VI (BS-VI) technology for new vehicles in two years. Delhi cannot afford to stagnate and remain moribund with only one archaic PUC programme that was originally designed for older technologies. This is becoming increasingly ineffective and even irrelevant for more advanced emissions control systems in the newer fleet that need a very different policing approach to keep them low-emitting on the road. This reality of Delhi is real for other cities of India as well.

What does remote sensing do?

Those who are yet not clear about the scope of its benefits may summarily dismiss this idea as science fiction. Let us look deeper. This move is consistent with the global regulatory programmes. Simply put, remote sensing is a light source and a detector that is placed on the side of the road or at a height to transmit a laser beam to measure exhaust emissions remotely via spectroscopy as vehicles pass by and cross the light path. This can measure exhaust plume, and detect opacity, nitric oxide, carbon monoxide, hydrocarbons, and carbon monoxide in 0.5 seconds in the exhaust plumes of vehicles. It can record emission rates from thousands of individual vehicles along with speed and acceleration across all driving conditions daily. This can test several vehicles per hour within an interval of one second. A camera captures the image of the vehicle’s number plate which, if connected with a vehicle registration database, can identify the make, model, certified emission standard, fuel type, rated power and other details.

It has many uses. At one level, remote sensing helps to detect individual high-emitting vehicles, where high emissions result from poor vehicle maintenance by the vehicle owner, or are caused by the removal and tampering of emission control systems and accidental malfunctioning of emission control equipment among others. But the other big benefit is that it also helps to detect high-emitting vehicle models where the fault lies with the vehicle manufacturer. These could be poor design or defects in the emissions control components; deterioration or poor durability of the emissions control-related components; and intentional cheating of emissions standards and the use of defeat devices.

In a scenario where only 23 per cent of Delhi’s vehicles turn up for PUC tests and escape the legal net of scrutiny, remote sensing can net them in to screen more efficiently in a non-intrusive manner. In a single day, a remote sensing can measure thousands of vehicles—several times the capacity of what PUC systems can do. It can catch vehicles if their emissions increase before the next PUC testing is due. It can help to characterise the fleet to identify the worst set of vehicles that contribute most to pollution; assess their usage pattern; and also identify vehicles that come from outside the city and are not registered. Images can help to identify irregularity in number plates. As vehicles do not come in contact with any testing machine or testing inspector, there is no scope of fraud that plagues the PUC system. This can even help to evaluate if the PUC system is working properly.

Certainly not a science fiction in India

Not many people know or can recall that field trial of remote sensing has been carried out in the past in Delhi and Pune—way back in 2004-05. When the Union Ministry of Road Transport and Highways (MORTH) had set up a committee under Automotive Research Association of India (ARAI) to make recommendations on inspection and certification centres in India, the committee had recommended, if the ongoing field trials on remote sensing devices in India find that these are effective in identifying grossly polluting vehicles then these could be used as supplementing tool in I/M system. Vehicles that escape PUC tests can be apprehended and forced into compliance. At that time, the costs were considered prohibitive.

Field trials that were conducted in Delhi and Pune worked very well for cars. But initially, there were hiccups in measuring emissions from two and three-wheelers. It was explained that the devices were not aligned with the tailpipes of these small vehicles; that these vehicles have relatively smaller plumes of emissions that decay quite fast before a minimum number of readings can be taken. Thus, capture rate is low.  Thus, the ARAI Report of the Technical Committee on Inspection and Certification System in India for MORTH noted that out of total measurements in the pilot scheme, 92 per cent of the total results for cars and 78 per cent of the total results for buses and trucks were valid, but for two wheelers, only 28 per cent of the results were valid. More innovation is expected to have taken place since then.

Delhi will have to reinvent the programme again. Several questions are being asked already. Can this work on the congested roads of Delhi for instance? Information available from China shows that these can work effectively with a traffic speed of around 25-30km/hour. In Chinese cities, the data scatter is between 10km/hour to 50 km/hour. It is expected to work with peak hour speed of 15-20 km/hour. On an average, a device is expected to cost about Rs 2.5 crore. Most Chinese cities have about 10 to 15 devices. Experts say a city like Delhi can do with about 10 or even less devices with strategic monitoring to begin with. It is possible to meet the incremental cost from the fund created from the environment compensation charge collected from each truck entry into Delhi.

Kolkata takes the lead: There are surprises in India too. Perhaps no one in Delhi has ever noticed that Kolkata is the only and the first city that has taken the lead to implement remote sensing measurements on a limited scale since 2009. After the Calcutta High Court had directed a phase out of older vehicles it had also directed improvement in in-use emissions surveillance. Even today, the city is using two monitors and is capable of generating at least 4,000 data sets a day. These operate for 8 working hours and five days a week at strategic locations. When we visited the Transport Department office at Beltola Road in Kolkata, we saw the extensive system in place that records and issues show-cause notices to the vehicle owners whose vehicles are found to be high emitting based on remote sensing measurements. They informed us that they have mobile remote sensing devices and these are placed in strategic locations by rotation.

They are issuing show cause notices to vehicle owners. We saw these are directly addressed to the vehicle owners with the license plate numbers. For instance, there is a show cause notice “for plying of the vehicle found to be emitting smoke beyond permissible level”. It mentions the date and the location where the vehicle was detected with high pollution level. It also gives the emissions results for CO, CO2, HC, NOx and smoke. It makes reference to the PUC limit values as per the 115 and 116 of Central Motor Vehicle Rule, 1989. The vehicle owner was requested to bring the vehicle to a specified inspection centre for verification within 15 days. Failing that, the owner would be liable to payment of fine under section 190(2) of Motor Vehicle Act and such other action per law. The notice carried the picture of the vehicle with registration plate and the emissions results compared with PUC norms (see photo of a show cause notice based on remote sensing measurements).

However, the officials shared that when vehicle owners are intimated by the department about their polluting vehicles they are often challenged on the grounds that they have a valid PUC certificate and should not be penalised. They felt that the MORTH needs to clarify how remote sensing monitoring will co-exist with the PUC programme.

Photo of a show-cause notice based on remote sensing measurement in Kolkata

Why renewed interest globally?

Scarred by the widespread incidents of emissions fraud and mounting evidence of very high on-road emissions from diesel vehicles even after meeting the Euro VI standards, regulators globally are alert and are relying more on high tech policing. Already, real world emissions monitoring with a portable emissions monitoring system is in place. But the entire on-road fleet still requires screening. Such large scale screening is possible only with remote sensing. The review of these systems done by the International Council on Clean Transportation (ICCT) shows that remote sensing measurements are more reflective of real-world conditions as measurements happen when vehicles are passing by under different ambient environmental conditions.

Worldwide, remote sensing is used for two regulatory approaches—“dirty screening” that identifies vehicles that are not in compliance and are high emitters, and are sent for proper inspection. The other is “clean screening” that identifies clean vehicles, and exempts them from regular emissions inspection testing. This reduces the cost of inspection testing and also improves public acceptance of the programme. This technology is used to supplement and evaluate the conventional inspection and maintenance programme.

Remote sensing has been more widely used in the US where several states have adopted remote sensing to identify high emitters and notify drivers that inspection and repair is needed. They exempt clean vehicles from regular tests. The share of vehicles that can obtain such a remote sensing-based clean screen certificate is up to a maximum of 30 per cent of vehicles.

China is using remote sensing since 2005 and by the end of 2016; around 70 cities in seven provinces and the two municipalities of Beijing and Tianjin have adopted remote-sensing programmes. At present, the Jing-Jin-Ji region of Northern China comprising of 26 cities, has about 160 remote sensing sets installed. An additional 140 sets will be installed in the coming year. This does not include mobile units. It is about 10 devices per city, although Beijing has about 30 of these units. In 2017, China’s Ministry of Environmental Protection or MEP issued a national regulation for measuring pollutants in exhaust from in-use diesel vehicles using remote-sensing equipment. According to the ICCT review of 2017, China is the first country in the world to implement such a programme at a national level. The regulation replaced all local standards related to monitoring diesel vehicle exhaust emissions with remote sensing. It defines a uniform protocol for local agencies to follow if they are implementing a remote-sensing programme. It aims to eliminate the top 5 per cent of high emitting vehicles, and it applies to both, light-duty and heavy-duty diesel vehicles. Vehicles that fail remote-sensing testing are either required to be sent for regular inspection testing to verify noncompliance or are directly sent for repair until they pass the inspection testing.

Hong Kong also has applied remote sensing successfully. A study carried out by the researchers of the University of Technology Sydney, Australia, Vocational Training Council, Hong Kong and Environmental Protection Department, Hong Kong, have looked at large dataset of on-road diesel vehicle emissions. They found that the emission rates were highly skewed for the dirtiest 10 per cent vehicles and also for larger engine size.  High-emitters occur in all vintages but decreases with newer manufacture.

Makes sense for us too

Given the inherent weaknesses of the PUC programme in Delhi and other cities of India that is plagued by very low level of compliance, inadequate calibration of equipments, a lack of audit of PUC centres, improper tests, and vulnerability to fraud—there is virtually no alternative mechanism to ensure that all vehicles are brought under robust surveillance. This poses serious risks as all emissions control equipments are designed for certain efficiency and durability for the life span of the vehicles. If vehicles are not watched carefully for good maintenance practices, quality manufacturing and emissions cheating, the polluted cities of India can be in serious trouble.

In fact, remote sensing results in other countries have demonstrated how this helps the regulators to evaluate the durability of emissions control systems and track the emissions performance of vehicle fleets over time on road. In the US, as the ICCT study shows, remote sensing detected increasing nitrogen oxide emission rate from diesel vans/pick-up vehicles that were equipped with selective catalytic reduction or SCR systems for NOx control from vehicle models of 2009. Their emissions had increased by more than 50 per cent within just three years of service for model year 2011, 2012, and 2013 vehicles. There are fears that if the same rapid deterioration takes place in Europe that has much larger share of diesel vehicles, there can be a significant NOx problem. In fact, several European cities are already facing it.

Delhi and the rest of India cannot escape the reality that it is time to grow up and grow out of PUC. There is a big mismatch between emissions benchmarks and exacting testing requirements for new vehicles on the one hand and outdated surveillance of emissions from on-road vehicles on the other. Cities need several levels of filters and checks today. Upgraded PUC can continue for the older fleet. The large advanced automated vehicle inspection centres that MORTH is setting up in 10 locations across the country (with two already established in Juljuli near Delhi and Nasik in Maharashtra), are also needed for more rigorous tests for both emissions and road worthiness of commercial vehicles. But these expensive centres are too few to meet the humongous demand for periodic inspection of millions of vehicles. Therefore, another filter of remote sensing is needed to supplement all these other efforts to screen the entire fleet that has not been possible so far.

It is time to think of a paradigm shift in the entire ecosystem of vehicles. If India is not too poor to motorise then it can and certainly needs to mobilise resources for smart policing of emissions on road to reduce high exposures and public health risks. Equally smart fiscal approaches based on the polluter pay principle can be adopted to recover the cost of investment and deliver public good.

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  • KOLKATA already started on 2010. But calibration is important factor when ambient air quality is far beyond the limit. Positive side of this remote sensing system is to test the vehicle on actual driving condition with laden weight. Like existing PUCC from auto emission testing centre it's not in idle starting stranded condition.
    But during the test no other vehicle should infiltrate the testing zone otherwise getting the correct readings of particulate matters , Nox ,Sox, Co, HC etc etc not possible

    Posted by: Somendra Mohan Ghosh | 4 months ago | Reply