Qualification: 
Ph.D
m_mithun@cb.amrita.edu

Dr. Mithun Mohan currently serves as an Assistant Professor (Sr. Gr.) at the department of Civil Engineering, Amrita School of Engineering, Coimbatore Campus.

Education

  • July, 2013 – February, 2017 : Ph. D.
    Transportation Engineering from Indian Institute of Technology Roorkee
  • July, 2008 – May, 2010 : M. Tech.
    Transportation Engineering from Indian Institute of Technology Roorkee
  • July, 2004 – May, 2008 : B. Tech.
    Civil Engineering from Kerala University

Professional Experience

July, 2018 - Present Assistant Professor
Amrita Vishwa Vidyapeetham, Coimbatore, Tamil Nadu
August, 2017 - July, 2018 Assistant Professor
MES College of Engineering, Kuttippuram, Kerala
May, 2013 – March, 2017 Senior Research Fellow
Indian Institute of Technology Roorkee
January, 2012 - October, 2012 Assistant Professor
Heera College of Engineering & Technology, Thiruvananthapuram
August, 2010 – December, 2011 Deputy Design Engineer
Feedback Infrastructure Pvt Ltd., Bangalore

Publications

Publication Type: Conference Paper

Year of Publication Title

2019

Mithun Mohan and Chandra, S., “Influence of Conflicting Stream's Composition on Critical Gap at Unsignalized Intersections”, in 98th Annual Meeting of Transportation Research Board, Washington D. C, 2019.

2017

Mithun Mohan and Chandra, S., “Queue Clearance Rate Method for Estimating Passenger Car Equivalents at Signalized Intersection”, in 96th Annual Meeting of Transportation Research Board, Washington D. C., 2017.[Abstract]


This study explores the use of queue clearance rate method for estimating passenger car equivalents (PCE) at signalized intersections. PCE is estimated based on the assumption that the rate at which a queue of vehicles clears the intersection is a function of its composition. Results of this method is compared with some of the popular techniques for PCE estimation. A four-legged intersection was simulated in VISSIM software and different techniques were used to convert the traffic mix into a uniform one. Parameters of VISSIM were modified to closely reflect the traffic behaviour under heterogeneous traffic conditions. All approaches of the intersection were loaded to saturated conditions and accuracy of estimated PCEs were established by comparing converted flow (PCE/h) with the capacity of an all-car traffic stream. Method based on saturation flow delivered the best result, but its use was limited to traffic composed only of two types of vehicles. Results of regression and optimization techniques were almost similar and the converted flow was close to the capacity of all-car stream. However, accuracy of these methods largely relied on the correct measurement of saturation flow. Queue clearance rate method does not require value of saturation flow and yielded good estimates of PCE throughout the simulation runs. The maximum difference between the converted flow and capacity estimated with all car situation was found to be less than 10 percent in all cases considered in this study.

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2016

Mithun Mohan and Chandra, S., “Influence of major stream composition on critical gap at two-way stop-controlled intersections”, in 95th Annual Meeting of Transportation Research Board, Washington D. C., 2016.[Abstract]


Gap acceptance method is the most popular technique for the analysis of two-way stop controlled intersections. This technique assumes that major street traffic is uninterrupted and minor street drivers are consistent and homogeneous. The present study found a clear difference in the traffic characteristics of major street at the intersection and upstream of it. The inter-arrival time distribution of vehicles is significantly modified when the vehicles approached the intersection. This indicates that gaps in the major street traffic at the intersection are modified due to the forced entry of lower priority movements. It also results in reduction of speeds of major street vehicles when they approach the intersection area. This phenomenon was observed in the field and speeds of different categories of vehicles were significantly lower at the intersection than those at 100 m upstream of the intersection. Earlier studies show that the popular methods of critical gap estimation are not useful in mixed traffic conditions. Therefore, this study uses Occupancy Time method, which takes into account the manner in which a vehicle clears the intersection. Data were collected at five intersections located in semi-urban area in different part of India and analysed to estimate the critical gap for two categories of vehicles (motorized two-wheelers and cars) and two priority movements (right turn from major and minor) at these intersections. Critical gap values for a vehicle was found to vary from one intersection to another although they are similar in geometry. This is attributed to the proportion of large size vehicles in the conflicting traffic. A statistically strong relation is found between the critical gap of a vehicle type and the proportion of large size vehicles in the conflicting traffic.

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2015

Mithun Mohan and Chandra, S., “New Methods of PCU Estimation at Unsignalized Intersections”, in RATE 2015, National Conference, SVNIT Surat, India, 2015.

2014

S. Chandra, Mithun Mohan, and Gates, T., “Estimation of critical gap using intersection occupancy time”, in 19th International Conference of Hong Kong Society for Transportation Studies, Hong Kong, 2014, Z. Leng., pp. 313–320.[Abstract]


A new method is proposed in this paper for estimation of critical gap at two-way stop controlled intersection under limited or no priority conditions in India and other developing nations. The method is based on the distribution of gaps (or lags) and time during which the intersection is occupied by the priority movement. The method is used to determine critical gaps of different types of vehicles under two diverse conditions of traffic flow; one as observed in developed country like US and another as observed in developing country like India. It is shown that the occupancy time method produces reasonable results under both the conditions. Critical gap values estimated by the new method are compared with those obtained from the maximum likelihood method, which is the most frequently used method in literature and it is found that the proposed method yields the results which are very close to those obtained from Maximum Likelihood Method.

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Publication Type: Journal Article

Year of Publication Title

2018

S. Chandra and Mithun Mohan, “Analysis of Driver Behaviour at Unsignalized Intersections”, Journal of Indian Roads Congress, vol. 79-2, no. 675, pp. 5-10, 2018.[Abstract]


Road accidents and associated fatalities in India have risen over the years and has reached a condition where approximately 17 lives are lost in an hour. Accident statistics identified drivers’ fault as the major contributor towards accidents on Indian roads. This study checks whether driver behaviour could feature as the main reason behind accidents at unsignalized intersections in India. A comparison is drawn between critical gaps on the basis of data collected at unsignalized intersections from India and USA. Maximum likelihood method was used in the estimation of critical gaps. Critical gaps of cars at an intersection in India were compared with those of a similar intersection in USA and with the values given in Highway Capacity Manual (HCM). Further, critical gaps for motorized two-wheelers were also estimated. It was found that at intersections of similar geometry, critical gap of cars for various movements in India were much less than in USA and this difference was in the range of 20-31%. Critical gaps of cars executing different movements at Indian intersections were consistently lower (up to 57%) than the base values given in HCM. Motorized two-wheelers, which were involved in majority of accidents at intersections, had even lesser critical gaps than cars. Lesser critical gap of Indian drivers in comparison to their western counterparts indicates their aggressive and risk taking behaviour, which often leads to road accidents. Thus, it is not very surprising to have drivers’ fault as the major reason for accidents in Indian intersections.

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2018

Mithun Mohan and Chandra, S., “Influence of major stream composition on critical gap at two-way stop-controlled intersections–a case study”, Transportation Letters: the International Journal of Transportation Research, pp. 1–8, 2018.[Abstract]


Gap acceptance method used in the analysis of two-way stop-controlled intersections is based on the assumption that major street traffic is uninterrupted. However, the present study found a clear difference among the traffic characteristics of the major street at the intersection and upstream of it. The distributions of inter-arrival times and speeds of major street vehicles are significantly modified as they approach the intersection. Data collected from five intersections in India were used to estimate the critical gaps for motorized two-wheelers and cars executing two non-priority movements (right turn from major and minor streets). Critical gap, estimated using occupancy time method, was found to vary among intersections, even when they were similar in geometry. This is attributed to the proportion of large-size vehicles in the conflicting traffic. A statistically strong relation is found between the critical gap of a vehicle type and the proportion of large-size vehicles in the conflicting traffic.

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2018

Mithun Mohan and Chandra, S., “Three methods of PCU estimation at unsignalized intersections”, Transportation Letters: the International Journal of Transportation Research, vol. 10, pp. 68–74, 2018.[Abstract]


Estimation of passenger car unit (PCU) is a vital component of any traffic study conducted in developing countries owing to the heterogeneity in the vehicular traffic. Past studies on PCU factors are majorly limited to intercity and urban roads. However, PCU factors for different types of vehicles on unsignalized intersections have not been investigated so well. This paper presents three methods of estimating PCU factors for different types of vehicles on unsignalized intersections under highly heterogeneous traffic conditions. The first method is based on the occupancy time of a vehicle while clearing the intersection. The second method is based on the capacity of a priority movement estimated in terms of different vehicle categories. Queue clearance rate is used as the basis for PCU estimation in the third method. Data were collected at two unsignalized intersection in semi-urban area of two cities of India and PCU for different types of vehicles is determined using the three methods. The resulting values of PCU factors were found to be logical and are representatives of the actual field conditions.

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2018

Mithun Mohan and Chandra, S., “Passenger Car Equivalents for Unsignalized Intersections in India”, Current Science, vol. 114, no. 6, pp. 1346-1352, 2018.

2018

Mithun Mohan and Chandra, S., “Critical gap estimation at two-way stop-controlled intersections based on occupancy time data”, Transportmetrica A: transport science, vol. 14, pp. 316–329, 2018.[Abstract]


Critical gap estimated at four Indian intersections using six popular techniques revealed a wide variation and many of these values are found to be unrealistically low. It indicates that all these methods are not adequate to address the complex traffic behaviour that exists in heterogeneous and non-lane-based traffic environment. A new method based on the occupancy time (OT) of a vehicle in the intersection area is proposed for the estimation of critical gap under mixed traffic conditions. The method is demonstrated to provide reasonably good results when applied to the data collected at one intersection in the US also. The correctness of the proposed method is further demonstrated by comparing the field capacity of a non-priority movement at one of the intersections with the theoretical capacity. It is found that the proposed method gives the capacity which is closer to field capacity than those estimated by the maximum likelihood method or modified Raff method.

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2017

Mithun Mohan and Chandra, S., “Queue clearance rate method for estimating passenger car equivalents at signalized intersections”, Journal of Traffic and Transportation Engineering (English Edition), vol. 4, pp. 487–495, 2017.[Abstract]


This study explored the use of queue clearance rate method for estimating passenger car equivalent (PCE) at signalized intersections. PCE was estimated based on the assumption that the rate at which a queue of vehicles clears the intersection is a function of its composition. Results of this method were compared with the results estimated by some popular techniques. A four-legged intersection was simulated in VISSIM software and different techniques were used to convert the traffic mix into a uniform one. Parameters of VISSIM were modified to closely reflect the traffic behaviour under heterogeneous traffic conditions. All approaches of the intersection were loaded to saturated conditions and accuracy of estimated PCEs were established by comparing converted flow (PCE/h) with the capacity of an all-car traffic stream. Method based on saturation flow delivered the best result, but its use was limited to traffic composed only of two types of vehicles. Results of regression and optimization techniques were almost similar and the converted flow was close to the capacity of all-car stream. However, accuracy of these methods strongly relied on the correct measurement of saturation flow. Queue clearance rate method did not require value of saturation flow and yielded good estimates of PCE throughout the simulation runs. The maximum difference between the converted flow and capacity estimated with all car situations was found to be less than 10% in all cases considered in this study.

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2016

Mithun Mohan and Chandra, S., “Review and Assessment of Techniques for Estimating Critical Gap at Two‐way Stop‐controlled Intersections”, European Transport Journal, vol. 61, p. 8, 2016.

2016

Mithun Mohan and Chandra, S., “Concept of queue clearance rate for estimation of equivalency factors at priority junctions”, Canadian Journal of Civil Engineering, vol. 43, pp. 593–598, 2016.[Abstract]


Traffic in developing countries is often distinguished from others for its diversity in vehicular composition and passenger car equivalents (PCE) becomes essential in such conditions for expressing traffic volume in terms of equivalent number of passenger cars. The PCE estimation at two-way stop-controlled intersections in developing countries is further complicated by the lack of movement priority and lane discipline. The study introduces a method to find PCE factors based on the time taken by a queue of vehicles to completely clear the intersection and composition of the queue. The method is validated through simulations in VISSIM software and was then used to derive PCE factors for three intersections in India. Although the method is developed and tested to estimate PCE factors under highly heterogeneous traffic at priority junctions in India, it is quite general in nature and can be used in traffic conditions found in developed countries as well.

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2014

R. Rastogi, Chandra, S., and Mithun Mohan, “Development of level of service criteria for pedestrians”, Journal of Indian Roads Congress, vol. 75-1, p. 60‐69, 2014.[Abstract]


Pedestrian facilities are provided to facilitate and encourage for short distance travel. The Level of Service (LOS) criteria available in the literature for pedestrian facilities are more adaptable to the pedestrian scenarios in the US than in a developing country like India. This paper presents the LOS criteria under two conditions, one for pedestrian movements along the carriageway on or at its side and other for the movement on a pedestrian facility. Data were collected in two different years (2007 and 2009) for the above mentioned two conditions. The LOS criteria were developed using two different approaches and the two data sets. One approach is based on the rate of change of curvature of the pedestrian flow-area module curve and another is based on speed ratio-density plot. It is observed that the pedestrian space criterion is more uniform and stable than the pedestrian flow criterion in defining the LOS of a facility. The suggested criterion for sidewalks and wide sidewalks will be very useful in revising the IRC codes on pedestrian facilities.

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