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GPS-fitted buses operating in bus rapid transit systems (BRTS) of India make it easier to collect a wealth of travel-time data from them. This article evaluates the operational performance of BRTS routes based on GPS data. First, various simplified statistical range parameters, viz. coefficient of variation percentile travel time, travel-time distributions, etc. are selected for route evaluation. Then, two bus routes of the Ahmedabad BRTS are selected as case study to develop and validate a methodology for evaluating the performance of these routes based on selected parameters. Weekday bus travel-time data for one direction accounting for 2124 bus trips are used in the study. The study then compares travel-time reliability-based performance of a BRT and a non-BRT route. Further, the study proposes an approach to measure a shift in BRTS network level of service based on two indices – average travel time per kilometre, and travel-time coefficient of variation. A left shift in cumulative plot indicates an improvement in the BRTS network level of service in the year 2016 compared to 2013.

Between 2008 and 2015, bus rapid transit system (BRTS) in India increased its implementation from two cities to eight cities with a significant increase in total ridership. This paper attempts to give a detailed review of BRTS implementation in cities of India. This is a systematic effort that could inform readers about the current system and network characteristics of Indian BRTS. Different system and corridor characteristics including off board and on board ticketing systems are adopted in India. Gross cost revenue collection model is adopted by almost all special purpose vehicle (SPV) companies developed to manage BRT systems. A variety of carriageway concept designs for BRTS are implemented in these cities considering a right of way of 22, 24, 30, 32, 40, 45, 60 meters respectively. Out of the eight cities, Ahmedabad has almost 30% of the total fleet size. In terms of regulatory context, SPV companies are formed in almost all eight cities after observing Ahmedabad BRT success. Documentation of these operating systems shall provide a sound database to planners and decision makers actively involved with BRT system implementation in developing countries.

A new monitoring scheme, based on the concept of onsite visualization (OSV), was successfully applied for monitoring safety conditions during construction of a long span cantilever bridge in Delhi Metro Phase-II project in 2010. The bridge construction with challenging features included a 100 m long span over the Northern Railways tracks passing below, the balanced cantilever construction methodology with a see-saw condition of the pin-connected girder during segment casting processes and a horizontal curvature of the girder with 300 m radius. The light-emitting sensors with dual functions, namely sensing and simultaneous visual output of measured results, were employed in this project and played crucial roles to capture unique behaviours of the bridge under construction and to ensure safety throughout the project.

The worldwide known relationship between transport and air pollution is demanding innovative solutions for satisfying the mobility needs with minimum pollution. While reducing the mobility demand is a longterm target, the most commonly adopted approach is to decongest the ‘hot spots’ having an alarming level of pollution. The main objective of providing bypasses and expressways is to divert the through traffic coming into the city. Delhi is one of the most congested and polluted cities in India. Among the various sources, vehicular pollution is a significant source of air pollution. Different policies and strategies have been developed to decongest and depollute Delhi. The Eastern Peripheral Expressway (EPE) is one such option implemented to decongest the national capital of India by diverting the traffic not destined for Delhi. It becomes essential to evaluate the performance of such significant infrastructural investments for better decision making in the future. Accordingly, the present study quantifies the impact of constructed EPE in terms of diverted traffic and the reduction of vehicular pollution from the capital of India. For this, various primary surveys like classified traffic volume, origin–destination and fuel station surveys were conducted in the study area. Vehicle kilometre travelled for all vehicle types was calculated using the primary data, and this parameter is considered for quantifying vehicular emissions. The results showed that reduction of vehicular emission due to diverted traffic was 0.7% of PM (PM2.5), 7.1% of NOₓ and 2.5% CO in the total vehicular emission load of Delhi.

The ever-increasing traffic congestion on urban roads leads to uncertainties in travel time necessitating the need to consider travel time reliability in measuring the efficiency of the transport system. In view of this, an attempt has been made in this study to examine the travel time reliability under the influence of various demand and supply side factors of the transportation system. For this purpose, an urban corridor of 2.5 km on National Highway 2 in the city of Delhi was considered. The traffic volume, speed and travel time data for one week were collected to analyse the travel time reliability on this stretch and estimated appropriate reliability measures. In order to assess the impact of various demand and supply side variations on travel time reliability, a microscopic traffic simulation model was developed using VISSIM software. The developed simulation model was successfully validated with the observed data and it was found from the analysis that travel time increases 5.3 and 6 times for the scenarios of increase in demand by 50% and lane closed for about 30 min respectively.

The present study demonstrates the application and usefulness of travel time reliability as a level of service (LOS) measure for urban arterial and inter-urban highway corridors on Indian roads. For travel time estimation, automatic vehicle license plate number data were collected through TrafficMon system. This system is a fully video-based enforcement system designed to measure the speed of vehicles passing in view of the camera, and read the vehicular license plate number. This system was implemented at the entry and exit side of the identified three study corridors and data were collected during morning and evening peak periods. The data were analysed and various travel time reliability measures were evaluated. The study also attempts to correlate reliability measures such as planning time (PT), buffer time (BT), planning time index (PTI) and buffer time index (BTI) with volume-to-capacity ratio which is the most widely used LOS measure for Indian roads. Analysis of results indicated that at LOS B the travel time of intercity highway was 40–46 sec/km, whereas it was 64–80 sec/km and 75–135 sec/km for urban uninterrupted and interrupted corridors respectively. The planning time for LOS B was more on urban arterial corridors when compared to inter-urban corridor for the same width of the carriageway. The upper limits of LOS B for PT were 132 sec/km and 63 sec/km for uninterrupted urban corridor and intercity highway corridor respectively. Other parameters of reliability like PTI and BTI were also evaluated and their values for different ranges of volume-capacity ratio were presented for identified corridors.

Periodical evaluation of the transit system and its subunits is becoming paramount for improving its performance. This article evaluates the performance of 12 routes of the bus rapid transit system operating in Ahmedabad, India. The performance indices considered in the study were divided into five major types of efficiency, viz. route design, scheduled design, cost, service delivery, and comfort and safety efficiency. Super efficiency data envelopment analysis was used to estimate efficiency scores for each type. Further, composite efficiency of routes was estimated based on analytical hierarchy process technique.

Dust is a generic term used to describe fine particles that are suspended in the atmosphere. Sources of dust emitted directly into the air are due to vegetation, burning of biomass, industrial and construction of activities, wind-blown, etc. Dust can be defined in practical terms as any particle from a few nanometres (nm) to a few micrometres ( mu m) in diameter that can become suspended in the atmosphere. According to the British Standard code (BS 6069-2) super(1) dust is defined as a solid particulate matter (PM) 1-75 mu m in diameter. Dust can be formed due to particles which are emitted directly and secondary particles which are formed by chemical processes in atmosphere. Particle size is an important factor influencing the dispersion and transport of dust in the atmosphere and its effects on human health. Particles less than 10 mu m in diameter (known as PM sub(10)) are often inhal-able, while particles less than 2.5 mu m are considered respirable (known as PM sub(2.5)). Particle size less than 10 mu m can cause health hazards, whereas those greater than 10 mu m are associated with public perception and nuisance super(2). PM sub(10) is of more concern to human health as the particles can enter the lungs, causing breathing and respiratory problems, with long-term health effects. These particles also carry adhered carcinogenic compounds into the lungs super(3).

The main objective of this study is to estimate the capacity of hybrid bus rapid transit (BRT) corridor. By the term hybrid BRT corridor in context to this study, we mean a corridor in which buses have to operate in an exclusive environment as well as in a mixed traffic environment. Capacity is an important parameter to estimate corridor and system performance. Therefore to evaluate the same, Ahmedabad BRT system was chosen in the present study. On the basis of boarding alighting data, the busiest route comprising both segregated (exclusive environment) and unsegregated (mixed traffic environment) stretch was selected. For estimating the capacity, an empirical method was adopted. Bus lane capacity for segregated stretch and unsegregated stretch was estimated as 243 buses/h and 101 buses/h respectively. The overall capacity value of hybrid BRT corridor was minimum of the two, i.e. 101 buses/h. After estimating the capacity so obtained, the effect of mixed traffic environment on overall corridor capacity was observed. Further, an attempt was made to estimate capacity using conventional Greenshield model on a mid-block section. Following this, the results of two approaches namely, empirical model capacity and capacity using Greenshield model were compared. The capacity obtained at mid-block section of the segregated stretch was overestimated by 19.34% or 290 buses/h compared to that obtained using empirical method (243 buses/h).

The present study deals with the geochemical and geochronological studies of monazite from Kandivalasa–Dibbalapalem coast, north Andhra Pradesh. The average concentration of ThO 2 and UO 2 from beach sands is 11.38 and 0.40 wt.% and from dune sands is 11.94 and 0.63 wt.%. The average REE from beach and dune sands is 58.64 and 57.94 wt.% and they are rich in La, Ce, and Nd. The most common characteristic feature to all monazite shows that the total REE content exceeds that of the actinides (Thru). Monazite that formed after the garnet break down contains significantly higher amounts of Y and HREE in fine sediments. The chondrite-normalized REE distribution patterns of monazite show uniformly enriched light rare earth element (∑LREE) which could be due to the preferential incorporation of lighter lanthanides and positive europium anomalies indicate that monazite was formed from magma/anatectic melt with high oxygen fugacity. Back-scattered electron (BSE) images of monazite showing compositional zoning and the bright outermost rim which is attributed to the influence by variations of LREE, HREE, U, Th, Pb and Y concentrations. The primary controlling factor, radiation damaged monazite yields in most cases significantly, with a strong dependence on the degree of metamictization based on the BSE intensity. The geochemical dating (U–Th–Pb) of monazite ranging age from 487 to 977 Ma from grain interior, can signify the age of Grenvillean evolution. This interpretation changes the existing tectonothermal history of the northern Eastern Ghats Belt. Our data show that the two adjacent crustal domains of the Eastern Ghats Belt show distinctly contrasting Neoproterozoic histories.