Laboratory # 8: Isolated Intersection Capacity Analysis
Background
This portion of the design project will bring together into one project the following concepts:
· Cycle length optimization,
· Phase splits,
· Pedestrian phasing,
· Intergreen time,
· Nema phasing,
· Measures of effectiveness (performance measures), and
· Signal coordination.
For this project, design teams will work on the Moscow subsystem that they have been assigned (their subnetwork).
Scope
Step 1
The first step of the design process is basically putting all of the information together into a useful form and determining how the system will be evaluated. This step includes the following:
· gathering information (volumes, PHF, signal timing)
· establishing an inventory of all the significant features of the subnetwork
· creating a model in SYNCHRO
· determining the model limits
· locating sources for performance measures
o (v/c) ratio
o Delay
o Queue length vs queue storage
o Percent stopped
· Documenting all of the above
Once the above has been accomplished you are ready to begin analyzing the system in the second and third steps.
Step 2
The second part of the design process is the analysis of existing conditions using the existing signal timing plans. This will cover the analysis of the existing subnetwork using existing 15 minute flow rates. The analysis should be performed at two levels as follows:
· individual intersections—consider the items listed below
o intersection delay
o queuing vs queue storage
o lane group (v/c) ratios
o excessive lane group delay
o percent stopped
o pedestrian service
o safe intergreen times
· subnetwork—consider the items listed below
o system delay
o percent stopped in the system
o intersection problems affecting system operations
· Document all the above
After completing the second part of the design process, you should have a list of deficiencies in the system as it operates now and these should include those deficiencies that have been observed in the field (these may be the most important).
Step 3
The third part of the design process involves the design of an improved signal timing plan for your assigned subnetwork given existing conditions and will include the following:
· For each intersection determine the following:
o Phase plan
o Cycle length
o Phase splits
o Intergreen times
o Ped phase
· For the subnetwork of intersections, determine the following
o Determine the best common cycle length—make sure that these work for all subnetwork intersections
o Changes needed in intersection phasing in order to improve system operations
o Modifications needed to existing intersection geometry
· Document all the above
Deliverable
· Full deliverable due in two weeks. This is an analysis of all of the intersections in your respective subnetworks.
· Partial deliverable due Monday next week at the end of the day. This is an analysis of the intersection of the intersection of Washington and Jackson, excluding the analysis of all other intersections.
· Create the partial and full reports with the following guidelines:
o will be double spaced.
o will be in hardcopy format.
o will be no longer than 10 pages in length (4 pages for the partial report).
o body of discussion must be in 12 point font with at least one inch margins.
o will use figures and tables to support your discussion.
o will have all referenced data, figures, tables, and calculations included in the body of the document. The appendix is for supporting information that is not directly referenced in the text. In other words, if I need to see the information to follow the discussion then put it in the body of the report.
o will sound like you understand the situation and are not afraid to explore why things are the way they are. Anybody can write a document summarizing numbers and actions taken. I expect you to interpret the numbers, explain why they are what they are, and defend why you did what you did.
o will be well written containing few writing errors
o will be consistent in its formatting and organization.