ENVIRONMENTAL IMPLICATIONS OF CARBON FOOTPRINT & ITS ESTIMATION

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1 ENVIRONMENTAL IMPLICATIONS OF CARBON FOOTPRINT & ITS ESTIMATION Promila 1, Dr. Nisha Kumari 2 1 Research Scholar, Department of Environment Science and Engineering, Guru Jambheshwar University of Science and Technology, (India) 2 Assisstant Professor, Centre of Excellence for Energy and Environment Studies, Deenbandhu Chhotu Ram University of Science and Technology, (India) ABSTRACT With the growing traffic in Delhi, the time period of stopping at signalised intersections has increased leading to delay. This has led to a lot amount of fuel wastage and an additional pollution load to the atmosphere. This study depicts a comparison among the loss in economic and environmental terms at selected intersections in Delhi for the year 2005 and The carbon footprint due to idling of vehicles at selected sites was calculated for both the years. The greenhouse gas (CO 2 ) showed at drastic upheaval from a level of ton in 2005 to ton in 2013 owing to 600 intersections in Delhi which shows a 19% increase in the CO 2 emissions due to idling from the year 2005 to The fuel loss and time loss concurred was calculated in monetary terms which also showed a gradual increase from 2005 to 2013 level. The study is limited to signalised intersections only. Keywords: Carbon Footprint, Delay, Idling, Intersection I. INTRODUCTION The increase in vehicles lead to an increase in traffic jams and also increases the timings of the red signals. This leads to increased time of vehicle idling, more consumption of fuel and more emissions of greenhouse gases. The vehicles emit a large volume of exhaust gases at the ground level, and the primary emission being of carbon dioxide. Although CO 2 is regarded as a gas of utmost importance but its increase after certain limit trap heat in the earth atmosphere and lead to greenhouse effect. The carbon dioxide emitted by burning a particular quantity of octane could be calculated by balancing the above equation. The density of octane is found to be 0.803grams/millilitre and thus 0.93 gallon of octane is present in 1 gallon of fuel (a mixture of hydrocarbons) which produces 14.1 pounds of carbon dioxide per gallon of fuel consumed. The relationship between gallons used over a given distance and miles per gallon (mpg) is not linear. The running vehicles at the time of idling also add a significant amount of emissions to the atmosphere in the form of exhaust gases. This leads to the conclusion that motor vehicles pollute, whether operating on expressway or parked in the driveways indicating that a running engine always emit some amount of pollutants. 459 P a g e

2 Fuel consumption also depletes stocks of non-renewable fossil fuels. Total fuel consumption can be decreased by reducing vehicle travel or reducing fuel consumption rate (improving fuel economy). Use of motor vehicles can reduce the quality of the air environment through polluting exhaust gases such as nitrogen oxides and hydrocarbons, evaporative emissions from fuel systems, particles in the exhaust gases of diesel vehicles, particles from tyre and brake wear. Motor vehicles reduce the quality of the water environment through discharges to the environment which are eventually washed into waterways. This can result from material shed on the roadway from tyre and brake wear and oil leaks. Non-productive activities such as vehicular idling lead to many problems harming humans and environment. Idling tailpipes spew out the same pollutants that form unhealthy smog and soot as those from moving cars. Nitrogen oxide, particulate matter, carbon monoxide and volatile organic compounds are the main health-harming pollutants in vehicle emissions. Apart from the healthharming pollutants the fossil fuel wastage during idling puts a load on fuel economy and the major heat trapping gas (CO 2 ) is also emitted. Mathur et al. (2009) reported that traffic signals have become an invaluable tool in ensuring smooth flow of motor vehicles at crossings. Consequently, with orderly flow of traffic, we lose huge quantity of fuel at crossings and creating the pollution for already polluted environment. This is because people often leave the engine of their vehicle running while waiting at signals (Idling). During no load running mode (idling) of the vehicular engine, the air supply is restricted by the nearly closed throttle and the suction pressure is very low. This low pressure condition gives rise to backflow of exhaust pressure, results an increase the amount of residual gases and reducing the fresh mixture inhaled. In a study conducted by Gill (2010) idling was said to increases dilution and cause the combustion to be erratic, irregular and slow which results in poor thermal efficiency and higher exhaust emission. At part load and idling the compression ignition engine presents even more favourable relative fuel consumption than the spark ignition engine. The extra fuel consumption at the traffic signals is much higher because of the irresponsible behaviour of the driver/rider and lack of determination towards stopping the wastage of fuel. In a study conducted by Mustafa et.al (1993), the authors concluded that there exists a direct relationship between vehicle emissions and traffic volumes at urban intersections regardless of traffic control. They stated that in general a signalised intersection produce 50% more emissions than an unsignalised roundabout. In case of higher traffic volumes the hydrocarbons generated by traffic signals is twice as high as that generated at roundabouts. In another study conducted by Varhelyi in Sweden (2002), it was found that CO emissions, NOx emissions and fuel consumption (per car within the influence of the junction) can be reduced by 29 percent, 21 percent and 28 percent respectively by replacing a signalised intersection with a roundabout. Vlahos et al. (2008) found that vehicular emissions are relatively high around intersections as vehicles have to slow down or stop at intersections, producing more emissions than when they are travelling at a constant speed. Traffic demand, vehicle types and types of intersection control are other factors that can influence vehicular emissions. Coelho et al. (2006) and Vlahos et al. (2008) reported that signalised intersections outperform other intersection types for higher traffic demand producing minimal emissions. Guensler (1993) in his work stated that the vehicular activities producing emissions are quantified and coupled with activity specific emission rates to obtain the sum total of motor vehicle emissions. The emission rates in 460 P a g e

3 gram/mile or gram/hour can be developed from vehicular activity of miles of travel or engine idling under various operating and environmental conditions. Parida and Gangopadhyay (2008) reported an approximate saving of 68 percent in fuel wastage and 71 percent in economic loss due to fuel wastage when engineering/management measures were applied at the selected 12 intersections, to estimate the savings in delays and on the basis of the savings accrued at low, medium and high volume intersections. Kumar et al. (2011) in his report says that vehicle emission is highly dependent on driver s behaviour and also the local driving cycle; hence vehicle emission is significantly affected by local road, traffic, vehicle and their delay and driving pattern. This paper depicts a comparison among the loss in economic and environmental terms at selected intersections in Delhi for the year 2005 and II. METHODOLOGY 2.1. Site Selection Delhi, the national capital of our country is experiencing an increase in the traffic volume and is known among one of the congested cities. The idling time hence gets increased at intersections in Delhi leading to more emissions of greenhouse gases. Based on the traffic volume count surveys conducted at selected intersections in Delhi by CSIR-CRRI, the sites for heavy (Ashram Chowk), medium (KG Marg) and low traffic volume (Shakti Nagar) were selected. The locations are chosen as per the availability of data and survey conducted at the selected intersections Traffic Volume Count Traffic volume studies are conducted to determine the number of vehicles, movements and to classify them into motorised and non-motorised vehicles. Traffic count was conducted for 24 hours at a given location. The traffic count was performed at 3 intersections which were divided as low, medium and high volume based on the volume of traffic at intersection based. The methodology adopted for conducting traffic volume count is based on total number of vehicles enumerated at four locations i.e. entering, exiting right, exiting straight and exiting left of each of the approach of an intersection. An observational checklist was used to describe the characteristics of the study location Delay and Idling Fuel Consumption To estimate the delays occurring at the selected intersections the data required are the hourly traffic volume at intersection and the average delays. A classification of the cars was done based on the type of fuel used (petrol, diesel or CNG) by the data collected from nearby fuel survey station. The delay for high volume intersection was found to occur for 20 hours and for low volume and medium volume intersection was found to occur for 14 hours out of the 24 hours traffic volume survey conducted at all the three intersections. Vehicular delay during different hours of the day was calculated was multiplying the average delay (in seconds) by the average hourly classified traffic volume. 461 P a g e

4 Idling fuel consumption of the individual vehicle was determined by running the vehicle idle for 1 hour in the campus premises. The fuel consumption tests at idling were performed by the use of flow detectors (FP Series). Table 1 depicts the amount of fuel consumed during idling by vehicle types. Table1. Idling Fuel Consumption S. No. Type of Vehicle Type of Fuel Idling fuel consumption 1. Cars Petrol Diesel CNG Two wheelers Petrol Auto (3W) CNG Mini Bus CNG Bus CNG W Goods CNG LCV Diesel HCV Diesel MAV Diesel Estimation of Fuel Loss and Determination of CO 2 produced The fuel loss due to idling was estimated by multiplying total delay determined (in hours) by idling fuel consumption (lit. or kg/hour) of corresponding vehicle. It could be mathematically expressed as: Fuel Loss (in litres or kg) = Delay (in hours) Idling Fuel Consumed (in litres or kg/hour). The CO 2 emitted from the idling fuel consumed is determined by following the guidelines established by IPCC (The Intergovernmental Panel on Climate Change), Estimation of Economic Losses Economic losses of fuel due to idling in terms of rupees are calculated by multiplication of fuel losses by the prevailing fuel rates in particular vehicles. The average fuel rates for the year 2013 were Rs for petrol, Rs for diesel and Rs for CNG and for the year 2005 were Rs , Rs and Rs for petrol, diesel and CNG respectively. The fuel losses in litres are enumerated in the previous section of the paper. The economic losses of time are calculated by multiplying per day income with delay in hours and occupancy. The annual per capita income in Delhi is taken as Rs. 2, 01,083 and per day income is Rs The mathematical expression could be given as: Economic Loss of Time = Per Capita Income Occupancy Delay (hours). 462 P a g e

5 2.6. Comparison between acquiesced data for the year 2005 and 2013 After data acquisition, a comparison was made between the acquiesced data for the year 2005 and 2013 collected from CRRI and a great variation was found which clearly signifies an increase in the number of vehicles. The vehicular increase leads to increase in traffic jams and longer red signals which cause more delay at idling and hence, more consumption of fuel during idling which consequently causes more carbon footprint. An increase in the carbon dioxide leads to global warming and the global temperature has been increasing from a decade. A comparison is derived between the year 2005 and 2013 for the locations: Ashram Chowk, Shakti Nagar and KG Marg. III. RESULTS 3.1. Comparison between fuel consumed and CO 2 emitted for the year 2005 and 2013 at the selected signalised intersection: As the traffic volume and delay has increased drastically from 2005 to 2013, there has been an increase in the fuel consumption due to idling and hence, correspondingly elevated levels of carbon dioxide. The fuel lost for the year 2005 at Ashram Chowk, KG Marg and Shakti Nagar is L, 537.3L and 658.2L respectively while, for the year 2013 is L, L and L respectively. Similarly, a drastic increase is found in carbon dioxide emission which for the year 2005 at Ashram Chowk, KG Marg and Shakti Nagar is ton, ton and ton respectively while, for the year 2013 is ton, ton and ton respectively. This is also tabulated in table 2. Table2. Comparison between idling fuel loss and CO 2 emitted for the year 2005 and S. No. Intersection Idling fuel loss (litres) CO 2 emitted (tons) Ashram Chowk KG Marg Shakti Nagar The graph plotted between the fuel loss and CO 2 emission for the year 2005 and 2013 (figure a, b, c) clearly shows elevated levels of fuel consumption and carbon footprint in P a g e

6 Bar Diagram Showing The Changes In Idling Fuel Lost And CO 2 Emission At The Three Intersections For The Year 2005 And 2013 (a) Line diagram depicting idling fuel loss (c) Line diagram depicting CO 2 emission for the year 2005 and for the year 2005 and Comparison among The Economic Losses For The Year 2005 And 2013 At Selected Signalised Intersection With the increase in the traffic volume, delay and fuel consumption, the economic losses in terms of money have also increased and show a great variation. The fuel loss at Ashram Chowk intersection was Rs in 2005 which increased to Rs in 2013, at KG Marg intersection from Rs in 2005 to Rs in 2013 and at Shakti Nagar intersection increased from Rs to Rs in Similarly, the time loss shows an increment from Rs in 2005 to Rs in 2013 at Ashram Chowk intersection, from Rs in 2005 to Rs in 2013 at KG Marg intersection 464 P a g e

7 and, from Rs in 2005 to Rs in 2013 at Shakti Nagar intersection. This is tabulated in Table 3. Table3. Comparison between economic losses for the year 2005 and S. No. Intersection Fuel loss (rupees) Time loss (rupees) Ashram Chowk KG Marg Shakti Nagar A comparative graph plotted as shown below (figure d) establishes a comparative relationship between the different emission parameters. Comparison among economic losses for the year 2005 and 2013 IV. CONCLUSION Delhi faces a challenging problem of greenhouse gas emissions leading to major consequences at global level. The 14% GHG emissions are contributed by the transport sector which is growing with the overwhelming population. Idling of vehicles contribute a lot to the emissions as well as the economic loss of fuel and time in terms of money. The total carbon footprint from 600 signalised intersections in Delhi per day in 2005 was ton and in 2013 was ton which shows a 19% increase in the CO 2 emissions due to idling from the year 2005 to P a g e

8 V. RECOMMENDATIONS Various suitable mitigation measures could be adopted to accredit the idling emissions and losses. Coordination and optimisation of signal time, strategies to conserve fuel through increased patronage of public transportation system, appropriate land use and transport policy, restraining the motorized traffic, encouraging non-motorized modes, switch-off vehicles during red light phase and use of advance driver alert system, catching driver training at young age, construction of roundabout, flyover instead of signalized intersection are observed as suitable exploratory measures to reduce the idling emission at intersection. Other measures to cut the greenhouse emissions could be through focus on mobility management which encompasses a range of strategies like car sharing, car pooling, park and ride facilities, smart cards, telecommuting, parking cash out, low speed modes, smart growth & transit villages and road pricing policies. REFERENCES [1] Mathur M.L. and R.P. Sharma: Internal Combustion Engines, Dhanpatrai Publication, pg. no.368, [2] Gill P. S., Automobile Engineering-I S K Kataria & sons 2010, vol. 1, First Edition, pg. no [3] Mustafa, S., A. Mohammed and S. Vougias, Analysis of Pollution emission and concentrations at Urban Intersections, Compendium of Technical papers, Institute of Transportation Engineers, [4] Varhelvi A., Effects of Small Roundabouts on Emissions and Fuel Consumption: A Case Study, Elsevier Science Ltd., Sweden, [5] Vlahos E., A. Polus, D. Lacombe, P. Ranjitkar, A. Faghri, and B.R. Fortunato, Evaluating the Conversion of All-Way Stop Controlled Intersections into Roundabouts, Transport Research, Rec. no. 2078, pg. no , [6] Coelho M. C., T. L. Farias, and N. M. Rouphail, Effects of roundabout operations on pollutant emissions, Transport Research D, vol.11, issue 5, pg. no , [7] Guensler and Randall, Vehicle Emission Rates and Average Vehicle Operating Speeds, Dissertation; submitted in partial satisfaction of the requirements for the degree of Doctor of Philosophy in Civil [8] Transportation Engineering, Department of Civil Engineering, University of California, [9] Parida P. and S. Gangopadhyay Estimation of fuel loss during idling of vehicles at signalized intersections of Delhi, Journal of Indian Roads Congress, pg. no , [10] Kumar R., B. K. Durai, S. Wafaa, and C. Boswell, Comparison and evaluation of emissions for different driving cycles of motorcycles: A note, Transportation Research Part D, pg. no , [11] Tiwari K. P., R. N. Singh and J. B. Balwanshi, Fuel Wastage and Emission due to Idling of Vehicles at Road Taffic Signals, International Journal of Research in Engineering and Technology, vol. 2, issue 10, pg. no , [12] Shaheen S. A., T. E. Lipman, Reducing Greenhouse Emissions and Fuel Consumption, Sustainable Approaches for Surface Transportation, vol. 31, pg. no , P a g e