Phasing Plan Research Articles

Phasing real estate projects considering profitability and customer satisfaction

PurposeThe aggressive competition in the real estate market forces real estate developers to tackle the challenge of selecting the best project construction phasing alternative. The real estate industry is characterized by high costs, high profit and high risks. The schedules of real estate projects are also characterized by having large number of repetitive activities that are executed over a long duration. The repetitiveness, long duration of execution, the high amounts of money involved and the high risk made it desirable to leverage the impact of changes in phasing plans on net present value of amounts incurred and received over the long execution and selling duration. This also changes the project progress, and delivery time as well as their respective impact on customer degree of satisfaction. This research addresses the problem of selecting the best phasing alternative for real estate development projects while maximizing customer satisfaction and project profit.Design/methodology/approachThe research proposes a model that generates all construction phasing alternatives and performs decision-making to rank all possible phasing alternatives. The proposed model consists of five modules: (1) Phasing Sequencing module, (2) Customer Satisfaction module, (3) Cash-In calculation module, (4) Cost Estimation module and (5) Decision-making module. A case study was presented to demonstrate the practicality of the model.FindingsThe proposed model satisfies the real estate market's need for proper construction phasing plans evaluation and selection against the project's main success criteria, customer satisfaction and project profit. The proposed model generates all construction phasing alternatives and performs multi-criteria decision making to rank all possible phasing alternatives. It quantifies the score of the two previously mentioned criteria and ranks all solutions according to their overall score.Research limitations/implicationsThe research proposes a model that assist real estate market's need for proper construction phasing plans evaluation and selection against the project's main success criteria, customer satisfaction and project profit. The proposed model can be used to conclude general guidelines and common successful practices to be used by real estate developers when deciding the construction phasing plan. In this study the model is based on business models where all the project units are sold, rental cases are not considered. Also, the budget limitations that might exist when phasing is not considered in the model computations.Originality/valueThe model can be used as a complete platform that can hold all real estate project data, process revenues and cost information for estimating profit, plotting cash flow profiles, quantifying the degree of customer satisfaction attributable to each phasing alternative and providing recommendation showing the best one. The model can be used to conclude general guidelines and common successful practices to be used by real estate developers when tackling the challenge of selecting construction phasing plans.

Evaluation of social and economic values in textile manufacturing heritage sites: the case of Yazd

This paper aims to explore the social and economic values of textile manufacturing heritage sites in Yazd (Iran). A critical literature review was made to address the values of heritage. Then, the values of heritage were scrutinized based on industrial heritage sites in Yazd through the case study method. In-depth interviews with 12 experts were conducted, and the results showed that prior to reusing industrial heritage, its historical and cultural value should be recognized. The results also revealed that the holding of events at these sites with an impact on the collective memory should involve people. Moreover, adaptive reuse has had an impact on urban macroeconomics and created economic value added for locals. The results also confirmed that having multiple buildings inside a factory might help with the restoration phasing plan.

A MULTI-OBJECTIVE OPTIMIZATION FRAMEWORK FOR TRAFFIC SIGNAL DESIGN

Traffic signal design requires experienced traffic engineers to decide on the phasing plans and then timing plans can be optimized. However, the available guidance provides general recommendations for phasing planning; while, commercial software optimizes the timing plans and corresponding operation performance (e.g., best performance index). Furthermore, the performance index excludes safety factors. This research aims to develop a framework that can deliver a phasing plan by enumerating all possible solutions and then selecting the phase plan that achieves the objectives. These objectives are to minimize the severity, average delay, and queue length. A program (i.e., software) has been developed to perform these stages and deliver a sorted list of phase plans based on the assessment criteria considering different traffic patterns, different intersection lane configurations, and operation types for left and right turns. A validation exercise was performed to assess the effectiveness and practicality of the developed software. It includes designing a phase plan for fifteen American, Canadian, and Chinese intersections and comparing them against their actual phasing design in terms of safety, average delay, and queue length. The results show that on average, the safety level is improved by 19%; however, the delay and queue length increased by 33% and 13%, respectively. The results encourage extending the proposed framework to consider the phasing sequence and coordination in future work. Finally, it is found that the framework provides practical phasing plans in terms of safety and other operational aspects. The results encourage extending the proposed framework to consider the phasing sequence and coordination in future work. Keywords: Traffic Signal Optimization, Phasing Plan, Highway Safety Manual, Queue Length DOI： https://doi.org/10.35741/issn.0258-2724.58.1.37

Connected Vehicle-Cooperative Adaptive Cruise Control Algorithm to Divide and Reform Connected Vehicle Platoons at Signalized Intersections to Improve Traffic Throughput and Safety

The cooperative adaptive cruise control (CACC) algorithm is a simple and effective way to form small-headway platoons so that road capacity and traffic throughput can be improved. The CACC algorithm has been broadly discussed in relation to the highway driving environment where frequent stopping and merging are uncommon. This paper proposes that CACC can also benefit urban arterials, using the appropriate algorithm to predict platoon behavior with optimized trajectories to divide and reform platoons before and after signalized intersections, thus maintaining small, safe headways. Connected vehicle (CV) technology is the key to adapting and improving the CACC algorithm, as it enables the signal phasing plan to be sent to a target CACC platoon and allows vehicles to acquire real-time information from other vehicles in the platoon. In this research, a CV-CACC algorithm is proposed consisting of two functions: platoon division and platoon reforming. The new algorithm is also equipped with acceleration as a new control variable instead of speed, so that the platoon is able to accommodate sharp speed changes around intersections, something the baseline CACC is unable to accommodate. In this study, computer simulations have been conducted to test the reliability of the CV-CACC algorithm and compare its performance against the baseline CACC algorithm.

Low carbon transition at the township level: feasibility study of environmental pollutants and sustainable energy planning

ABSTRACT This paper addresses the role of low carbon transition in town planning. This study aims to fill a major research gap by exploring the topic of low carbon planning at the township level. This study is conducted through case study research in China. This study addresses two main stages of ‘target plan’ and ‘pre-masterplan’, which then feeds into a feasibility study comprised of five steps: (1) indicative analysis of CO2 emissions; (2) computational assessment of pollution dispersion; (3) development of a feasible phasing plan for low-carbon development implementation; (4) proposal for low carbon indicator system at the township level; and (5) detailed low carbon development plan. The findings include a dual carbon management plan and a breakdown of strategies, which are novel at the township level. The results contribute to the development of low-carbon town planning with the consideration of environmental pollutants and sustainable energy planning at the township level.

Study of Phasing Plan of Kalimati Water Treatment Plant Installation in Sidoarjo

One of the programs to increase clean water supply services in Sidoarjo district is maximizing water sources to serve 5 sub-districts in Western Sidoarjo, including Prambon, Tarik, Tulangan, Krembung and Balongbendo sub-districts, by planning a Water Treatment Plant (WTP) with total capacity of 1,000 LPS. The planning stages begin with calculation of projected water demands in 5 sub-districts for 10 years ahead. The results of projected water demands will be compared with the installation’s capacity to obtain the actual and initial staging plan for Water Treatment Plan’s constructions. Therefore, the construction and investment of Kalimati Water Treatment Plan could be arranged efficiently.

Empirical Study on Pedestrian Signal Design and Compliance in the State of Qatar

To ensure safe crossing manoeuvres at signalized crosswalks, the pedestrian delays and allocation of sufficient pedestrian green and flashing green times should be considered at design stage. The pedestrian signal settings in the State of Qatar were analyzed through empirical observations of eight crosswalks. Video recording technique was used to record the pedestrian movements and signal settings at selected crosswalks. The results indicated that excessive delays resulted in low compliance rates at all crosswalks and the signal phasing affected compliance rate. Moreover, the analysis of crossing speed indicated that the speed (1.2 m/s) currently specified by the Qatar Traffic Control Manual, 2015 for determining clearance time is sufficient for safe crossing. In addition, the results of speed analysis indicated that the gender, type of pedestrian signal display, and crosswalk length affect the crossing speed of pedestrians. A comparison of crossing times with the provided signal timings indicated that a lower pedestrian flashing green is provided at all sites, and excessively large buffer intervals are available. These results demonstrate the urgent need to modify signal settings to enable more opportunities for walking and legal crossings. It is recommended that pedestrian signals should be always activated based on the applied phasing plan without the need for pressing the push buttons. These push buttons can be used to recall early pedestrian green to reduce their waiting time. Furthermore, at major crossings, countdown timers showing time remaining for PG should be installed to improve compliance rates.

Traffic Signal Phasing Problem-Solving Rationales of Professional Engineers Developed from Eye-Tracking and Clinical Interviews

There is a lack of knowledge on the way transportation engineering practitioners engage with various Contextual Representations (CRs) to solve traffic engineering design problems. CRs such as equations, graphs, and tables could be perceived differently, even if they represent the same concept. The present study recognized left-turn treatment at signalized intersections as a prominent concept in traffic engineering practice and identified three associated CRs (a text-book equation, a graphical representation, and a stepwise flowchart) to design a phasing plan. Two data collection mechanisms were concurrently employed: 1) eye-tracking to analyze visual attention and document problem-solving approaches and 2) reflective clinical interviews to analyze ways of thinking and document problem-solving rationales. The problem-solving experiment was completed by twenty-four transportation engineering practitioners. Transportation engineering practitioners not only demonstrated preferences for different CRs, they also demonstrated different reasoning as to the selection of the same CR. Results of Multivariate Analysis of Variance showed that there was a statistically significant difference in visual attention based on CR. Additionally, in-vivo coding of participants’ interviews identified seven distinct rationales for CR selection. Findings from this study could be employed to modify transportation engineering curricula with optimized visual CRs.

Optimization of vehicle and pedestrian signals at isolated intersections

In most traffic signal optimization problems, pedestrian traffic at an intersection receives minor consideration compared to vehicular traffic, and usually in the form of simplistic and exogenous constraints (e.g., minimum green time). This could render the resulting signal timings sub-optimal especially in dense urban areas with significant pedestrian traffic, or when two-stage pedestrian crosswalks are present. This paper proposes a convex (quadratic) programming approach to optimize traffic signal timings for an isolated intersection with one- and two-stage crosswalks, assuming undersaturated vehicular traffic condition. Both vehicle and pedestrian traffic are integrated into a unified framework, where the total weighted delay of pedestrians and vehicles at different types of crosswalks (i.e. one- or two-stage) is adopted as the objective function, and temporal and spatial constraints (e.g. signal phasing plan and spatial capacity of the refuge island) are explicitly formulated. A case study demonstrates the impacts of incorporating pedestrian delay as well as geometric and spatial constraints (e.g., available space on the refuge island) in the signal optimization. A further analysis shows that a two-stage crosswalk may outperform a one-stage crosswalk in terms of both vehicle and pedestrian delays in some circumstances.

Optimization of an orbital long-duration rendezvous mission

The phasing segment of the rendezvous mission between a cargo spacecraft and a space station usually lasts for several weeks, and actually presents an orbital long-duration problem. In this study, this orbital long-duration problem is formulated as a mixed integer nonlinear programming (MINLP) problem in which the maneuver revolution numbers (integers), maneuver arguments of latitude and impulse magnitude are used as design variables at the same time. A hybrid approach is then proposed to solve this MINLP problem. First, a linear dynamics model considering the J2 term of the Earth non-spherical gravity is employed to formulate an approximate phasing problem, which is optimized using a genetic algorithm. Second, a shooting iteration process considering the coupling effect between the in-plane and out-of-plane maneuvers is proposed to improve the approximate solution to satisfy the terminal conditions of the high-precision problem. The proposed approach is demonstrated for a typical two-week rendezvous phasing mission. The results show that the proposed approach can stably obtain the near optimal high-precision solution by integrating the perturbed trajectory only a few times. Furthermore, a long-duration rendezvous phasing plan is compatible with any initial phase angles that the in-plane velocity increment remains almost unchanged when the initial phase angle changes. However, under the same conditions, the out-of-plane velocity increment has considerable variations. Compared with a two-day rendezvous phasing plan, a two-week plan could have several successive coplanar launch opportunities for the chaser by aiming different terminal revolution numbers.

Modeling Evaluation of Eco–Cooperative Adaptive Cruise Control in Vicinity of Signalized Intersections

Vehicle stops caused by traffic signals reduce vehicle fuel economy ratings along arterial roadways. Eco–cooperative adaptive cruise control (eco-CACC) systems are being developed in an attempt to improve vehicle fuel efficiency in the vicinity of signalized intersections. These eco-CACC systems utilize traffic signal phasing and timing data received through vehicle-to-infrastructure communication, together with vehicle queue predictions, to compute fuel-optimum vehicle trajectories that are continuously updated as the vehicle travels in the vicinity of signalized intersections. The algorithm computes a desired speed for the vehicle that is either displayed to the driver or directly integrated into the vehicle’s adaptive cruise control system. In this paper, the INTEGRATION microscopic traffic assignment and simulation software is used to evaluate the performance of a proposed eco-CACC algorithm to assess its networkwide energy and environmental impacts. A simulation sensitivity analysis demonstrates that as the market penetration rate of CACC-equipped vehicles increases, the energy and environmental benefits also increase, and that the overall savings in fuel consumption are as high as 19% when the market penetration rate is 100%. On multilane roads, the algorithm may produce networkwide increases in the fuel consumption level when the market penetration rate is less than 30%. The analysis also demonstrates that the length of control segments, the signal phasing and timing plan, and the traffic demand levels significantly affect the algorithm performance. The study further demonstrates that the algorithm may produce increases in fuel consumption levels when the network is oversaturated; thus, further work is needed to enhance the algorithm for these conditions.

Integrating 4D modeling and discrete event simulation for phasing evaluation of elevated urban highway reconstruction projects

Elevated urban highway reconstruction projects have complex geometry and limited space available, which may lead to spatiotemporal clashes. In addition, maintaining an acceptable flow of traffic without compromising safety in highway construction zones is another major issue for planners. This paper proposes a new method for generating and assessing reconstruction phasing plans and calculating the probability of stochastic spatiotemporal clashes associated with the optimal feasible phasing plan. A phasing plan assessment approach using a constraint-based system and 4D modeling is presented to define the feasible sequences in which the segments can be constructed or demolished. The result of this step is an optimal feasible phasing plan that meets a set of predefined constraints and creates no spatiotemporal clashes. This plan is then examined to calculate the probability of potential stochastic spatiotemporal clashes, which may happen when the variability of construction and demolition durations is considered, and to recommend the starting date of operations to minimize the probability of these clashes. The feasibility of the proposed method is explored through a case study.

A multi-path progression model for synchronization of arterial traffic signals

To contend with congestion and spillback on commuting arterials, serving as connectors between freeway and surface-street flows, this paper presents three multi-path progression models to offer progression bands for multiple critical path-flows contributing to the high volume in each arterial link. The first proposed model is a direct extension of MAXBAND under a predetermined phasing plan, but using the path-flow data to yield the progression bands. The second model further takes the phase sequence at each intersection as a decision variable, and concurrently optimizes the signal plans with offsets for the entire arterial. Due to the competing nature of multi-path progression flows over the same green duration, the third model is proposed with a function to automatically select the optimal number of paths in their bandwidths maximization process. The results of extensive simulation studies have shown that the proposed models outperform conventional design methods, such as MAXBAND or TRANSYT, especially for those arterials with multiple heavy path-flows. The research results from this study have also reflected the need to collect more traffic pattern data such as major path-flow volumes, in addition to the typical intersection volume counts.

METHODS FOR THE ASSESSMENT OF PERFORMANCE INDICATION MEASURES AT AMAKOM INTERSECTION AND THEIR APPLICATION IN MICRO SIMULATION MODELING

Signalized intersections are vital nodal points in a transportation network and their efficiency of operation greatly influences the entire network's performance. Traffic simulation models have been widely used in both transportation operations and traffic analyses because simulation is safer, less expensive, and faster than field implementation and testing. This study assessed performance indication measures at Amakom intersection using micro simulation models in Synchro/SimTraffic. Traffic, geometric and signal control data including key parameters with greatest impact on the calibration process were collected on the field. At 5% significant level, the Chi square test and t-test analyses revealed that headway had a strong correlation with saturation flow compared to speed for both field and simulated conditions. It was concluded that changes in phasing plan with geometric improvement would improve upon the intersection's level of service.

Mitigating Right-Turn Conflict with Protected Yet Concurrent Phasing for Cycle Track and Pedestrian Crossings

Where there are high turn volumes or speeds, pedestrian and bicycle crossings may need to be protected from right turns as well as left turns. Cycle tracks may need protected crossings even where right-turn volumes are modest. This research explores a phasing scheme in which right turns have their own phase and bike and pedestrian crossings run in their own distinct phase concurrent with the parallel vehicular through phase. This protected yet concurrent phasing scheme is more efficient than an all-pedestrian phase. A general framework for sequencing phases accounting for the right turn and crossing conflict is shown with four rings instead of the usual two. Seven examples of protected yet concurrent phasing from the United States and the Netherlands illustrate the scheme and characterize its likely impacts in terms of delay and street footprint. Overall delay and footprint impacts are found to be modest; factors that affect the impact of protected phasing include complexity of the phasing plan, coordination, and the possibility of using reservice. Because protected yet concurrent phasing makes efficient use of time, this phasing is also economical with space. Although the phasing requires right-turn lanes, its use can reduce the necessary number of through lanes, especially in comparison with all-pedestrian phasing.

용산공원 설계 국제공모 출품작에 나타난 프로세스적 설계 분석

용산공원과 같은 대형 공원의 설계는 특정 시점의 완결적 마스터플랜을 생산하는 전통적인 설계 방식보다는 다양한 층위에서 프로세스에 중점을 두는 접근을 필요로 한다. 본 연구의 목적은 '용산공원 설계 국제공모'(2012)의 여덟 개 출품작에 나타난 프로세스적 설계의 특성을 분석하는데 있으며, 이를 위해 각 출품작을 프로세스적 설계의 주요 대상, 단계별 계획 구성의 시간적 기준과 특징, 프로세스적 설계의 표현 방법 등 세 가지 기준으로 분석하였다. 본 연구는 프로세스적 설계 방법론의 현재 수준을 비판적으로 점검하는 동시에 국제공모를 통해 수렴된 용산공원의 미래 좌표를 보다 합리적이고 전략적인 방향으로 제안하는 이중의 의의를 지닐 수 있을 것이다. 각 출품작에서 프로세스를 계획한 대상은 공간의 물리적 개발 순서, 생태성의 복원 과정, 공공성의 회복 과정, 경제성을 고려한 운영계획의 순으로 나타났다. 주요 고려사항으로는 주변 도시 조직과의 연결, 광역 녹지 체계와 수 체계의 연결, 부지 내 기존 건물 및 기반 시설의 활용 등이 있었다. 단계별 계획의 시간적 기준은 크게 일정한 시점과 기간을 설정하는 것과 단계의 순서만을 설정하는 것으로 구분되었다. 프로세스적 설계의 표현 방법은 대부분 단계별 계획의 형식을 취하고 있었으며, 일부 작품에서는 시나리오 구성 등과 같은 방식이 시도되었다. 용산공원 설계 국제공모의 출품작들은 프로세스적 설계를 적극적으로 시도했다기보다는 프로세스적 설계의 방법 중 하나인 단계별 계획을 설계의 한 부문으로 도입했다고 볼 수 있다. 또한 전통적인 설계 관례인 마스터플랜 방식을 거부하기보다는 마스터플랜과 프로세스적 설계 사이의 절충적 입장을 취했다고 볼 수 있다. Designing large parks such as Yongsan Park requires the open-ended process-oriented design approach in complex layers rather than the conventional self-completed master plan method. This study aims to examine the characteristics of process-oriented design in the eight invited entries of "International Competition for the Master Plan of the Yongsan Park, Korea"(2012). For this purpose, it analyzed each entry according to three criteria: objects of process-oriented approach, time factor and its features of phasing plan, and presentation method of the process. This analysis can not only critically review the current level of the process-centered design methodology but also suggest strategic future directions for Yongsan Park. The objects of process-oriented design in the eight works were order of physical space development, restoration process of ecosystem, recovering process of publicity, and economic operation and management. Main considerations in the objects were connections to adjacent urban fabrics, links to regional green and water system, reuse of existing buildings and infrastructures in the site. The temporal criteria of the phasing plan had two aspects. One was planning a certain time and period, and the other was just establishing an order of phases. Most of the presentation method of process was the phasing plan, but some of the entries suggested a scenario plan. The eight works of "International Competition for the Master Plan of Yongsan Park" did not attempt process-oriented designs entirely and completely. Rather, they tried to introduce the phasing plan as part of a process-centered design. Also, they took an eclectic approach between master plan and process-oriented design instead of rejecting the conventional master plan approach.

New Formulation to Analyze Signalized Approaches

The procedures generally used in calculating capacity, level of service, saturation flow rate, delay, queue lengths, and signal timing for approaches to signalized intersections are based on disaggregating traffic flow into lane groups. These procedures can be complex if the approaches exhibit geometries with lanes that are both exclusive (i.e., dedicated to servicing a single traffic movement) and shared (i.e., servicing at least two traffic movements). The complexity is exacerbated if the signal timing contains multiple phases servicing the approach, particularly if both permitted and protected signal phases are involved. Finally, the averaging of the differing flow characteristics on each lane making up a lane group could yield results that are unrealistic. The Highway Capacity Manual (HCM) devotes many pages in Chapter 16 and its appendices to delineating these procedures. To a large extent, the HCM uses queue accumulation polygons as part of these procedures and is now considering an extension called the incremental queue accumulation method. This paper presents a new formulation that yields estimates of the traffic demand in each lane, by turn movement, for virtually all geometric configurations of signalized approaches and for all signal phasing plans. The formulation also yields the saturation flow rates by lane and the required signal phase durations for any stated phasing plan. The basis for this method is a variation of Wardrop's laws. The formulations are presented for common approach configurations, and illustrative numerical examples are presented to demonstrate their applicability.

New Formulation to Analyze Signalized Approaches

The procedures generally used in calculating capacity, level of service, saturation flow rate, delay, queue lengths, and signal timing for approaches to signalized intersections are based on disaggregating traffic flow into lane groups. These procedures can be complex if the approaches exhibit geometries with lanes that are both exclusive (i.e., dedicated to servicing a single traffic movement) and shared (i.e., servicing at least two traffic movements). The complexity is exacerbated if the signal timing contains multiple phases servicing the approach, particularly if both permitted and protected signal phases are involved. Finally, the averaging of the differing flow characteristics on each lane making up a lane group could yield results that are unrealistic. The Highway Capacity Manual (HCM) devotes many pages in Chapter 16 and its appendices to delineating these procedures. To a large extent, the HCM uses queue accumulation polygons as part of these procedures and is now considering an extension called the incremental queue accumulation method. This paper presents a new formulation that yields estimates of the traffic demand in each lane, by turn movement, for virtually all geometric configurations of signalized approaches and for all signal phasing plans. The formulation also yields the saturation flow rates by lane and the required signal phase durations for any stated phasing plan. The basis for this method is a variation of Wardrop's laws. The formulations are presented for common approach configurations, and illustrative numerical examples are presented to demonstrate their applicability.

CONVERSION OF A LARGE ROUNDABOUT IN BAGHDAD CITY TO A SIGNALIZED INTERSECTION

CONVERSION OF A LARGE ROUNDABOUT IN BAGHDAD CITY TO A SIGNALIZED INTERSECTION

Laboratory Design for Today’s Technologies and Marketplace

Many laboratories must be redesigned to adapt to rapid changes in equipment technology and in the business of health care. The information needed to select design goals can be gathered by following a three-step discovery process. Architectural and engineering plans may then be developed. The proposed design must address building and safety codes, the incorporation and anticipation of new technologies, productivity concerns, and marketing strategies. After existing conditions are defined and a design is developed, a detailed cost analysis can be performed. A phasing plan that spreads construction and costs over several years may be considered. Due to the complexity of a major laboratory redesign, an architectural and engineering firm with extensive laboratory design experience should be a key member of the project design team from the start.