Papers by Velmurugan Senathipathi
The major factor affecting road-user costs (RUC) is the speed at which vehicles operate on roads ... more The major factor affecting road-user costs (RUC) is the speed at which vehicles operate on roads which in turn determines fuel consumption and other cost components per unit distance travelled. Thus vehicular speed plays a significant role in highway economic evaluation. In the last decade, the Government of India has been involved in road capacity augmentation by building high-speed corridors to link major cities through the implementation of National Highway Development Programme (NHDP) projects such as Golden Quadrilateral, North-South, East-West, Expressway and Port Connectivity corridors. These recent radical changes in road network coupled with enhanced vehicle technology have resulted in huge variations in speed on these highways which has made it essential to evaluate the changing speed characteristics which are important inputs in estimation of RUC. An attempt is made in this article to study the speed characteristics on high-speed multi-lane corridors in plain terrain considering both straight and curved sections spread across the country. From the collected data, free-speed profiles of different vehicle types on high-speed corridors of India are developed and subsequently free-speed equations are developed considering the effect of roadway roughness.
DESCRIPTION Collection of Space Mean Speed (SMS) data, which finds application in many traffic en... more DESCRIPTION Collection of Space Mean Speed (SMS) data, which finds application in many traffic engineering problems, is tedious and cost ineffective in countries like India where automatic speed detection systems are not in vogue. In view of this issue, it was decided to express space mean speed as a function of a relatively conveniently measurable mean speed measure i.e. Time Mean Speed (TMS). Review of the already developed statistical models by using data collected under this study indicated that those models in their present form are not applicable for heterogeneous traffic conditions which are prevalent on Indian roads. Therefore, in this paper, appropriate modifications to the existing SMS models were effected using data collected on multilane divided National Highways in the National Capital Region of India.
Transportation Planning and Technology, 2011
This paper analyzes vehicular speeds at a micro level and studies the relationships between the i... more This paper analyzes vehicular speeds at a micro level and studies the relationships between the important elements of speed, namely space mean speed (SMS) and time mean speed (TMS) under heterogeneous traffic conditions. Vehicular speed data were collected at ...
Current science
During the last decade, developing countries such as India have been exhibiting rapid increase in... more During the last decade, developing countries such as India have been exhibiting rapid increase in human population and vehicles, and increase in road accidents. Inappropriate driving behaviour is considered one of the major causes of road accidents in India as compared to defective geometric design of pavement or mechanical defects in vehicles. It can result in conditions such as lack of lane discipline, disregard to traffic laws, frequent traffic violations, increase in crashes due to self-centred driving, etc. It also demotivates educated drivers from following good driving practices. Hence, improved driver behaviour can be an effective countermeasure to reduce the vulnerability of road users and inhibit crash risks. This article highlights improved driver behaviour through better driver education, driver training and licensing procedures along with good on-road enforcement; as an effective countermeasure to ensure road safety in India. Based on the review and analysis, the article also recommends certain measures pertaining to driver licensing and traffic law enforcement in India aimed at improving road safety.
During the last decade, developing countries such as India have been exhibiting rapid increase in... more During the last decade, developing countries such as India have been exhibiting rapid increase in human population and vehicles, and increase in road accidents. Inappropriate driving behaviour is considered one of the major causes of road accidents in India as ...
AbstractIn this paper, an attempt has been made to develop distress prediction models covering va... more AbstractIn this paper, an attempt has been made to develop distress prediction models covering varying types of distresses—namely, cracking, potholes, and roughness— prevalent on the low-volume fle...
Any transport facility is essentially a service being provided to the society. Therefore, it is e... more Any transport facility is essentially a service being provided to the society. Therefore, it is expected of the traffic engineers, transport planners and policy-makers alike to be able to understand and evaluate the quality of service that is being provided by the transport facilities designed by them. The level-of-service (LoS) concept was devised in the US Highway Capacity Manual (US-HCM) precisely for the above consideration. However, direct implementation of the US-HCM methods in India is not possible because of the heterogeneous traffic conditions and vastly unique driver behavior found on Indian highways. Therefore, it becomes imperative to evaluate other competing methodologies that may be more appropriate in defining the LoS being offered to the road users by Indian highways in general and multilane interurban highways in particular. Towards this end, this paper reviews in detail the LoS estimation methodologies that have been demonstrated to be suitable for application in t...
The present study demonstrates applicability of VISSIM software to determine capacity of multilan... more The present study demonstrates applicability of VISSIM software to determine capacity of multilane highways under mixed traffic flow conditions. Traffic flow data collected on a section of four-lane divided highway are used to develop the speed-flow curve. The same set of field data is used in VISSIM and simulated speed-flow curve is compared with field curve. It was found that VISSIM in its original form overestimates both speed and capacity of the highway. Driver behaviour parameters CC0 and CC1 are first determined for homogeneous traffic conditions having only one of the four types of vehicles in the stream and then results are aggregated to get the values of these parameters for a mixed traffic stream. Further analysis of field data with calibrated values of CC0 and CC1 indicated a good match between field and simulated capacity. The procedure is shown to work on another section of four-lane divided highway with paved shoulders, whereas simulated capacity was 5329 pcu/hr agains...
Journal of Transportation Engineering
Passenger car units (PCU) of different types of vehicles are required to convert a mixed traffic ... more Passenger car units (PCU) of different types of vehicles are required to convert a mixed traffic stream into a homogeneous equivalent, and thereby to express the mixed traffic flow in terms of equivalent number of passenger cars. Earlier studies have reported that PCU for a vehicle is dynamic in nature and changes with traffic volume and proportional share of a vehicle type in the traffic stream. The present study provides PCU values for different types of vehicles typically found on interurban multilane highways in India at different levels of service (LOS). Traffic simulation model VISSIM is used to generate the traffic flow and speed data for conditions that are difficult to obtain from field observations. Important VISSIM parameters are first calibrated to reflect mixed traffic flow behavior and then the software is used to draw the speed-volume relationships for cars and one of the remaining four categories of vehicles in the traffic stream. The proportion of second category of the vehicle was also varied to observe its effects on PCU values. Finally, PCU values are suggested for different type of vehicles at different LOS and for different traffic composition on four-lane and six-lane divided highways.
Since transport industry is essentially a service sector component, it is of paramount concern fo... more Since transport industry is essentially a service sector component, it is of paramount concern for the traffic engineers, transport planners and policyfacilities designed by them. US Highway Capacity Manual (HCM), with all its revisions since 1950, is the pioneer document in this respect as it quantified the concept of capacity for a transport facility and laid the foundations for estimating the level of service (LOS) being provided by that facility to its users. Unfortunately, the HCM methods developed in US are not directly applicable directly around the world due to the heterogeneities arising out of markedly varying local conditions. Recognizing this, several countries have developed their indigenous versions of HCM. Likewise, Indian highways, due to the heterogeneous traffic conditions and vastly unique driver behavior found on these roads, are also not conducive to the application of US HCM methods. Identifying this huge gap in knowledge, efforts were initiated by CSIR-CRRI to develop the Highway Capacity Manual for Indian roads (Indo-HCM). This paper, thus, presents a review of significant methodological issues that need to be specifically addressed to enable accurate estimation of roadway capacity for multilane highways, and based on the same, methods that can deployed for roadway capacity estimation in Indian conditions have been discussed.
Journal of Advanced Transportation, 2004
ABSTRACT The prediction of free speeds of vehicles is an integral part of the economic appraisal ... more ABSTRACT The prediction of free speeds of vehicles is an integral part of the economic appraisal of highways. It is to be noted that speeds not only govern the travel time costs, but also have major impacts on Vehicle Operating Costs (VOC). The World Bank has proposed a mechanistic free speed model based on the limiting speed concept for Highway Design and Maintenance (HDM)-III. This model along with some refinements has been included in HDM-4. The underlying assumption in the HDM free speed prediction model is that the free speed at any given point of time is the minimum of possible constraining speeds. This paper mainly addresses the methodology considered to update the free speed models through mechanistic principles (based on HDM-4). This is accomplished by calibration of the model using the current data on free speeds, road and vehicle characteristics. Subsequently, the validation of the developed models has been carried out.
During the last decade, developing countries such as India have been exhibiting rapid increase in... more During the last decade, developing countries such as India have been exhibiting rapid increase in human population and vehicles, and increase in road accidents. Inappropriate driving behaviour is considered one of the major causes of road accidents in India as compared to defective geometric design of pavement or mechanical defects in vehicles. It can result in conditions such as lack of lane discipline, disregard to traffic laws, frequent traffic violations, increase in crashes due to self-centred driving, etc. It also demotivates educated drivers from following good driving practices. Hence, improved driver behaviour can be an effective countermeasure to reduce the vulnerability of road users and inhibit crash risks. This article highlights improved driver behaviour through better driver education, driver training and licensing procedures along with good on-road enforcement; as an effective countermeasure to ensure road safety in India. Based on the review and analysis, the article also recommends certain measures pertaining to driver licensing and traffic law enforcement in India aimed at improving road safety.
Transportation Research Procedia
Journal of Traffic and Transportation Engineering (English Edition)
Transportation in Developing Economies, 2016
Any transport facility is essentially a service being provided to the society. Therefore, it is e... more Any transport facility is essentially a service being provided to the society. Therefore, it is expected of the traffic engineers, transport planners and policy-makers alike to be able to understand and evaluate the quality of service that is being provided by the transport facilities designed by them. The level-of-service (LoS) concept was devised in the US Highway Capacity Manual (US-HCM) precisely for the above consideration. However, direct implementation of the US-HCM methods in India is not possible because of the heterogeneous traffic conditions and vastly unique driver behavior found on Indian highways. Therefore, it becomes imperative to evaluate other competing methodologies that may be more appropriate in defining the LoS being offered to the road users by Indian highways in general and multilane interurban highways in particular. Towards this end, this paper reviews in detail the LoS estimation methodologies that have been demonstrated to be suitable for application in traffic scenarios characterized by high heterogeneity and lane indiscipline. Also, based on an exhaustive review of the literature, the study recommends that three to five categories of LoS in the stable-flow region may be explored for practical application in the Indian scenario as part of the ongoing research on development of an Indian Highway Capacity Manual.
INTERNATIONAL JOURNAL FOR TRAFFIC AND TRANSPORT ENGINEERING, 2015
The vehicles normally move at their free speeds when it is least impeded due to traffic flow unde... more The vehicles normally move at their free speeds when it is least impeded due to traffic flow under lean traffic (free flow) conditions. As traffic flow increases, the vehicles cannot sustain their free speeds due to interactions from other vehicles in the traffic stream. In addition to that the vehicles that are operating in the congested traffic conditions will consume more fuel than those operating in steady state traffic conditions for the same average speed. This leads to increase in travel time and fuel consumption of the vehicles and thereby adding to total road user cost (RUC). On the contrary, fuel consumption is also high at very high speeds under free flow traffic flow conditions leading to increase RUC. Considering these scenarios, the travel time and fuel cost of the vehicle due to the congestion and free flow conditions (uncongested) has to be necessarily modelled in order to estimate realistic assessment of RUC on Indian highways. In the present study, the congestion cost relationships have been developed between Congestion Factor, a ratio of cost under congestion and steady state conditions and Volume-Capacity Ratio by considering various vehicle types plying on varying widths of multi-lane highways (four, six and eight lane divided carriageways) through the collection of exhaustive time related and fuel related data. Time related data was collected through questionnaire survey method whereas fuel consumption data was collected using advanced sophisticated fuel flow measuring equipment (V-Box). The developed equations have been successfully applied to demonstrate their applicability in terms of estimating realistic effect of congestion on time and fuel cost by considering a section on NH-2 in Delhi. The analysis shows that the congestion effect is more significant on fuel cost for heavy commercial vehicles whereas it is more prominent on time cost for passenger vehicles. However, the congestion effect on combined fuel and time cost is more significant on multi-axle trucks followed by cars, two wheelers and buses.
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Papers by Velmurugan Senathipathi