Afzal Ahmed

NED University of Engineering and Technology | NED University · Department Of Urban and Infrastructure Engineering

Accurate depiction of existing traffic states is essential to devise effective real-time traffic management strategies using Intelligent Transportation Systems (ITS). Existing applications of Dynamic Traffic Assignment (DTA) methods are mainly based on either the prediction from macroscopic traffic flow models or measurements from the sensors and d...

Heterogeneous traffic in developing countries consists of motorbikes and cars as private vehicles along with various other modes of transport for public and commercial transport. Motorbikes and cars have distinct travel characteristics, having different travel times and owned by commuters from significantly different socioeconomic backgrounds. This...

The accurate depiction of the existing traffic state on a road network is essential in reducing congestion and delays at signalized intersections. The existing literature in the optimization of signal timings either utilizes prediction of traffic state from traffic flow models or limited real-time measurements available from sensors. Prediction of...

Traffic streams in many developing countries consist of various modes of transport, with high heterogeneity in driver behavior. Modeling these types of traffic streams, in which traffic rules (speed limit, lane discipline, etc.) are not strictly followed, is a complex task. A review of the existing literature shows that there is a lack of traffic f...

A significant difference in the behavior of heterogeneous and undisciplined traffic streams is observed when compared with the conventional traffic flow. Most of the existing traffic flow models are developed considering the traffic stream with strict lane discipline. Several studies from South Asian countries have reported high heterogeneity in th...

The development of smart cities relies on the implementation of cutting-edge technologies. Unmanned aerial vehicles (UAVs) and deep learning (DL) models are examples of such disruptive technologies with diverse industrial applications that are gaining traction. When it comes to road traffic monitoring systems (RTMs), the combination of UAVs and vis...

Roundabouts are among the widely used traffic control infrastructures, which function by defining priorities for various entry approaches and circulating traffic. In many developing countries, the priority rules are not implemented through pavement markings or road signs and drivers are also unaware of these rules. Thus, available gaps become the o...

This study evaluates the impact of exposing asphalt pavement to sewage and fresh water. In total, 87 samples were prepared, where half of them were immersed in sewage and the others were immersed in freshwater. The Marshall mix design method was adopted for the preparation of samples. Three immersed samples were tested for stability and flow every...

The technologies and sensors developed for standard traffic streams often fail to accurately measure the heterogeneous traffic with no lane discipline. This research proposes an efficient framework to measure traffic flow parameters in real-time using an unmanned aerial vehicle (UAV). The proposed framework in this research estimates road area occu...

An increase in urban traffic especially in developing countries like Pakistan has led to huge noise chaos on the major arterials with a lack of facilities to manage it. Such harmful excessive noise from road traffic creates a direct impact on the daily commuters and can have severe health consequences such as hearing loss, stress, and heart disease...

Background Road traffic injuries (RTIs) are a major public health concern for children. They are particularly less skilled in perceiving road hazards and are unable to take appreciate safety precautions as road-users. Traffic hazard perception training is a promising intervention to improve the safety skills of this vulnerable group. Aims This stu...

Polyester (PET) is used in asphalt binder to improve the sustainability and performance of the road. Modification of asphalt has become a serious demand these days due to performance requirements caused by significant traffic and heavy vehicles. Asphalt alone cannot bear the stresses. The Marshall Mix design method is used for testing treated and u...

In developing countries like Pakistan, economic instability, improper planning, non-optimal design, delays in construction, and unsustainability during the operations of transportation megaprojects cause an unnecessary burden on the national exchequer. Recently, several Bus Rapid Transit (BRT) projects have been initiated in Pakistan. The detailed...

A variety of methods have been proposed in the existing literature for the estimation of Passenger Car Equivalent (PCE) factors. These methods are based on the comparison of selected attributes of different vehicles. This research, for the first time, utilizes the basic notion of the linear relationship between road area occupancy and density for t...

This paper examines the carbon footprint of freight transport in Pakistan and evaluates the potential of improving the performance of freight transportation. This study is first of its nature from Pakistan on the quantitative evaluation of the sustainability of freight transport using limited available data. The trends in the mode share of freight...

Increased traffic flow results in high road occupancy. Traffic road occupancy is often used as a parameter for the prediction of traffic conditions by traffic engineers. Although traffic monitoring systems are based on a large number of technologies, challenges are still present. Most of the methods work efficiently for free-flow traffic but not in...

This research presents an in-depth microscopic analysis of heterogeneous and undisciplined traffic at the signalized intersection. Traffic data extracted from the video recorded using an unmanned aerial vehicle (UAV) at an approach of a signalized intersection is analyzed to study the within green time dynamics of traffic flow. Various parameters o...

Scrapped tires from vehicles are produced in large quantities. Despite numerous existing uses of scrapped tires, a large quantity ends up at the landfill sites, which contributes to environmental degradation. The development of more applications of scrapped tire usage can reduce the disposal of tires at landfill sites. This research proposes a nove...

This research calibrates Cell Transmission Model (CTM) for heterogeneous and non-lane disciplined traffic, as observed in Pakistan and some other developing countries by constructing a flow-density fundamental traffic flow diagram. Currently, most of the traffic simulation packages used for such heterogonous and non-lane-disciplined traffic are not...

Given the fact that the existing literature lacks the real-time estimation of road capacity and incident location using data from inductance loop detectors, a data-driven framework is proposed in this study for real-time incident detection, as well as road capacity and incident location estimation. The proposed algorithm for incident detection is d...

This paper analyses the behaviour of university students in their mode selection and their preference towards a proposed bus rapid transit (BRT) line in Karachi, Pakistan. This BRT line, known as Red Line, has a major portion of its route along the University Road. Most of the major higher education institutions of Karachi are located along Univers...

This study presents a comparative analysis of selected parameters of existing formal and informal Public Transport (PT) modes being operated on three different types of fuels. The performance of PT modes is analysed on fuel consumption, capacity, transportation cost, and emissions resulting from these modes. The required data were collected using r...

The merging and diverging of weaving flow with the through flow to reach the U-turn create a weaving section. The average speed of vehicles along the weaving sections has been studied as a function of through and weaving flow. However, the literature on the effect of the length of weaving sections on the average speed of vehicles along the weaving...

Traffic streams in most of the urban areas of developing countries are highly heterogeneous with poor lane discipline. Traffic simulation and optimization packages based on microscopic traffic flow models are popular for modeling traffic flow and optimizing traffic controls all around the globe. However, applying microsimulation packages to model u...

Freight and passenger transport accounts for approximately one third of total transport greenhouse gas emissions. Emissions from vehicles need to be accurately estimated to ensure that the air quality management is implemented appropriately. At present, Pakistan is lack in proper measurement and estimation of vehicular emissions. This study provide...

Accurate depiction of existing traffic states is essential to devise effective real-time traffic management strategies using Intelligent Transportation Systems (ITS). Existing applications of Dynamic Traffic Assignment (DTA) methods are mainly based on either the prediction from macroscopic traffic flow models or measurements from the sensors and d...

Short-term congestion caused due to traffic incidents or other road environment factors significantly reduces traffic flow capacity of a link which forms a major part of travel time delays. Accurate and reliable estimate of real-time traffic state is essential for optimizing network performance during unpredictable events. Inaccurate estimate of cu...

Road inventory and traffic volume demand maps are the most important elements of a working traffic management system. In some countries these up-to-date road inventory data are not available and 24-hour traffic counts are not frequently collected due to lack of funds or difficult to access remote places. The authors discuss a geospatial methodology...

The concept of the signal-free corridor is a very recent theoretical and practical contribution to urban transportation planning and design in Karachi, Pakistan. There is no theoretical underpinning available regarding the phrase 'signal-free corridor‘ within the cities around the globe both in MEDC‘s (More Economically Developed Countries) or LEDC...

Over the last few years, the rate of road traffic accidents in Karachi has increased considerably. Many precious lives have been lost on account of this menace. In the absence of a comprehensive road traffic accidents database, the problem of road traffic accidents was not properly addressed and got worse with time. The Road Traffic Injury Research...