Figure: Methodology of The Study

Abstract

Various measures, recommended or imposed by the Government of Bangladesh to control the spread of COVID-19, impacted the travel behavior of the urban travelers significantly. Showcasing high impacts while the lockdowns in place, similar research suggested that the effects of such will impact mode choice behavior significantly in a period after lockdowns as people blend in with new normalcy. This study aimed at examining the changes that occurred in travel and mode choice behavior after the repealing of lockdowns and models the change in the factors that affect mode choice. Data were collected through an online questionnaire survey, limited to Dhaka Metropolitan Area and dispersed through social media ad campaign, which included questions on trip purpose, mode choice, distance traveled, and frequency of trips before and after COVID-19 lockdowns. Two hundred and ninety-five responses were collected from the survey which were analyzed through non-parametric and parametric analysis to compare between pre-lockdown and post-lockdown periods. 

Processing and checking suitability of the data for models, Multinomial Logit Model was deemed representative of the behavior and different models for Before and After Lockdown situation, considering 3 different aggregation of modes were estimated (Public Transport was used as reference). Qualitative interpretation of various factors and their impacts on mode choice behavior was undertaken. As MNL does not allow for comparing between two different time periods, Interaction analysis was done, with the introduction of a time period dummy variable. Interaction of the dummy variable with other features were calculated and interaction model was estimated. It provided insights on which changes were truly significant, leading to steps and policy reformations to be implemented in case of a future lockdown/pandemic situation, so that public transport does not decline. 

Results explained that trip purpose, mode choice, cost of trip, frequency of trips and importance imparted on various Levels of Service (LOS) factors for the primary travel were significantly different before and after the lockdown. There was a significant shift from public transport to private transport and non-motorized modes while people placed a higher priority on the pandemic related concerns while choosing a mode during the pandemic as compared to the general concerns or trip attributes. Importance imparted on various vehicle characteristics, trip attributes and safety related attributes shifted significantly as travelers preferred shorter distance, shorter time and cost-efficient modes in pre-lockdown time, while preferring safer, higher cost, less distance and crowding to be more important factors in the new normal situation. Significant changes in factors affecting mode choice were observed, as household income, employment status and safety & distancing in vehicle impacted travelers to shift from public transport to private vehicles and non-motorized vehicles. Government authorities could utilize such knowledge for planning smart and partial lockdowns in the event of future lockdowns and also, utilize the knowledge in making the new public transportation systems to match users’ needs. 

Sample Results

Outcomes

1. Successfully identified and interpreted implication of safety and health related factors of vehicles on urban traveler’s behaviors and what makes them shift mode choice in new normalcy. Also, quantifiably identified shift in modal split in new normalcy and which key points are important to focus on to regain modal share for public transport.

2. Discerned focal points to prioritize on in case of a new pandemic/lockdowns and recommended policy reformation to not lose modal share of public transports. 

3. With Dhaka being the capital of a developing country, with various transportation projects being undertaken right now, forecasting use and feasibility analysis of future projects need to be reconsidered. Thus, the study opened a new door to for health related & psychological factors to be considered for the planning of future modes and such. 

Figure: Methodology of The Study

Abstract

For the completion of CE 454 - Transportation Engineering Sessional II Term Paper, we were tasked with analyzing the characteristics of the Russel Square - Panthapath Intersection corridor for traffic volume, speed-flow and potential bottlenecks were analyzed using simulation in PTV VISSIM. Statistical Analysis was conducted and the characteristics were quantified and compared with standards.

For Traffic Volume Analysis The data collected from all the groups were used to find composition, Design Flow Rate direction of flow, PHF (Peak Hour Factor). With the help of the data collection, an attempt had been made to understand the traffic patterns during different time periods. For Speed-Flow Characteristics Analysis, Maximum vehicle speed was found to vary between 15-20 kmph in Russell Square to Panthapath direction and 30-35 kmph in Panthapath to Russell Square. 50% of the observed vehicles were light vehicles. Various spot speed measures were obtained, which showed that free flow condition was not present on the corridor.

The frequency distribution curves in each direction were nearly symmetric along axis. Space mean speed was found to be less than Time mean speed. The Wardrop relationship was established and evaluated. Level of Service was found to be LOS F. Yearly cost in delay was found to be 33385971 BDT, which is a loss incurred on the country’s budget. Thus, a lane expansion project was evaluated to be beneficial for a 20-year design period. Furthermore, various other protective and control measures were recommended for betterment of the speed characteristics of the vehicles on the road. 

Sample Results

Outcomes

1. Determined the current state of speed-flow characteristics of the corridor and compared against baseline for Dhaka City. It broadened perspective on traffic analysis and methods utilized for such.

2. Identification of bottlenecks on the road and their implications depending on direction and time of day. The delay analysis result was converted to a monetary value that provided insights on cost of delay and determining feasibility of a potential expansion project.

3. Provided firsthand perspective on traffic analysis methods, data collection process and management. Also, gained insights into statistical analysis of raw data collected from field along with preparation for simulation of the system. 

Figure: Methodology of The Study

Abstract

A condition survey is the process of collecting data to determine the structural integrity, distresses, skid resistance, and overall riding quality of the pavement. The way surveys are conducted has vital influence on designs, on production of quantities and cost estimates and finally on execution of the work. In this study, the condition survey of the corridor from Russel Square to Panthapath Intersection was conducted to identify various geometric and operational conditions of the road. The survey was conducted manually, by walking survey method with photographs. Various roadway features, availability of constituents was observed, noted, and analyzed. Causes of side-friction and loss of road width were identified with approximate loss incurred by the deterrents. The study found the road to be adequate in terms of road conditions, however, aligning the condition with the initial purpose of the road made the condition to be unsatisfactory. Side frictions were constantly present with high frequency, leading to a low level of service at times. Various traffic control devices were installed in places, but they were dysfunctional or not operational, leading to flow being hindered. Furthermore, pedestrian crossing facilities were found to not be adequate with respect to the road being a link road with high-speed traffic. Various recommendations have been made to improve the condition of the road, both geometrically and operationally. 

Outcomes

1. Identified congestions and pain points along busy route.

2. Determined causes of side friction and corresponding reduced road width.

3. Road improvement measures were identified and policy recommendations were suggested.

The experiment is carried out by adding 10% RHA as a supplementary cementitious material (SCM) and incorporating different dosages of NF (0.1%, 0.2%, and 0.35%) in RAC. The RAC is made with 100% replacement of recycled coarse aggregate with natural coarse aggregate. The fiber length is 20 mm, the w/c ratio is 0.45, and the mix ratio of the components in the concrete mix is 1:1.5:3 (Cement: Fine Aggregate: Coarse Aggregate). Compressive strength test, split tensile strength test, and flexural strength (three-point loading) test are done to observe the combined effect of RHA and NF on the mechanical properties of RAC. The current research revealed that the combined effect of RHA and fiber has a positive effect on recycled concrete. The maximum increment is 16.9% in compressive strength, 5.21% in tensile strength, and 12.8% in flexural strength. Based on the experimental results, the optimal fiber content is 0.2%. From the outcome of the study, it can be said that using recycled aggregate concrete incorporated with RHA and NF can be used to replace conventional concrete. It will help preserve the natural materials from being overly used in construction which will be one step close to achieving sustainability