Intersection Analysis: Traffic Volume Studies and Characteristics
Course: 14.341 - Transportation Engineering
Semester: Fall 2005
Instructor: Nathan Gartner and Chronis Stamatiadis
Partner: City of Lowell, Division of Planning & Development
Intersections are of critical importance to the transportation system due to their influence on the movement and safety of traffic flow. The place of intersection is determined by design, and the act of intersecting is modified by regulation and control. Students were instructed to study the volume of vehicles passing a given point during specified periods of time. The traffic volume studies were done to obtain factual data concerning movement and counts of vehicles at selected points to compute capacity, evaluate congestion, analyze accidents and designing channelization or turn prohibitions.
The City of Lowell’s Master Plan takes into account the need to prepare for increasing pressures of the transportation system. Increased development generates additional traffic on Lowell’s roadways, impacting the quality of life for residents, employees, businesses and schools. City planners embrace an access-based transportation system that will accommodate traffic demand pressures through management and development of alternatives along with improving traffic flow to promote effective and safe transportation. Through this partnership effort, engineering faculty, students and city planners collaborated on investigating traffic congestion in order to develop suggestions and recommendations that work towards optimizing traffic signals of selected intersection arterials in the City of Lowell.
City of Lowell Transportation Engineer, Jeffrey Gomes, and Assistant Traffic Planner, Matthew Roux, gave an in-class presentation of city traffic concerns, traffic and engineering layouts, and GIS displays and overlays of city intersections. City engineers also provided the students with ATR data. The Assistant City Planner commented that, “I sure wish that this type of S-L was offered when I was training in such a program. I’m really glad to see the changes here in the university and the college of engineering through S-L. Both City professionals commended the S-L program with providing students the opportunity to work with real world situations.
Intersections are of critical importance to the transportation system due to their influence on the movement and safety of traffic flow. The place of intersection is determined by design, and the act of intersecting is modified by regulation and control. Students were instructed to study the volume of vehicles passing a given point during specified periods of time. The traffic volume studies were done to obtain factual data concerning movement and counts of vehicles at selected points to compute capacity, evaluate congestion, analyze accidents and designing channelization or turn prohibitions. Students were divided into two working groups in order to focus on two different city locations of interest. One group focused their traffic investigation on specific areas of Stevens Street, while the second group studied specific areas of Pawtucket Street. Student efforts pointed to current traffic needs that warrant installation of traffic signals at the intersections of concern.
Student reports were shared with the city. However, city planners were uncertain regarding quality of student data complied, which resulted in helpful suggestions for future partnership efforts. It was suggested that a city traffic study be developed as a two part or two semester process in order to complete a full study that included proper days and times of investigation (e.g., off time days such as Tuesday, Wednesday and Thursday rather than Monday and Friday). It was also recommended to engage students in the first semester in a fuller development of background information and methodology in terms of complete data (e.g., in field accident reports). After a fuller study during the first semester, then students could more fully develop their written reports in the second semester. City planners would be interested in having students develop a GIS layer for the city downtown parking areas, and associated costs required to develop parking suggestions.
Learning objectives met by the S-L project:
- Students calculated hourly flow volumes and developed intersection flow diagrams
- Students calculated peak hour factors (PHF) and measured signal timing to develop a timing pattern for the intersection of interest
- To expand the student’s knowledge of the traffic study methodologies
- To develop an intersection analysis
Community objectives met by S-L project:
- To have suggestions regarding what could or should be done to improve traffic concerns in the city
- To gain new insights and ideas for consideration
- City planners enjoyed the interaction with the students and faculty
- To provide valuable feedback to the city planners regarding traffic challenges and potential solutions