SECTION 16 TRAFFIC/SAFETY SECTIONS 16.1, 16.2 AND 16.3 ARE UNDER DEVELOPMENT 16.1-1
16.4 Intelligent Transportation Systems Introduction The ITS Engineering Unit is responsible for the design of all ITS facilities. These facilities include computerized Traffic Signal Systems, Incident Management Systems, VMS signs, HAR, ramp metering, system detection, Weigh-in-Motion (WIM), Automated Vehicle Classification (AVC), speed monitoring, emergency call, and Roadway Weather Information (RWIS) systems. Design Development The following is the design process for a Computerized Signal System and/or Incident Management System. 1. The designer will contact all pertinent state and local authorities and state agencies to discuss the project. 2. The designer will obtain and review all existing plans, studies, environmental impact documents and other pertinent information. 3. The designer will field survey the entire project for preparation of plans. 4. Designer prepares System Definition Report outlining the advantages and disadvantages of each alternate scheme of Traffic Control that is currently available or can be developed with current technology. The report shall include, as a minimum, the following major elements: a. Report on existing traffic conditions b. System operations c. System detection d. Closed Circuit Television e. Variable Message Signs f. Highway Advisory Radio g. Communications backbone h. Control Center i. Operations and Maintenance j. Opinion of probable construction cost k. Identify required permits 5. The designer will identify all required boring locations for proposed structures. Provide a geotechnical evaluation report, if and when directed by the Chief, Bureau of Geotechnical Engineering. 6. Identify all existing utilities within the project limits. Investigate and resolve any 16.4-1
overhead or underground conflicts with the proposed or existing traffic signal equipment. 7. The designer shall perform initial data collection ( before evaluation of a project): a. Traffic Control parameter data collection b. Traffic Signal data c. ATR counts d. Manual counts All Traffic Counts shall be summarized in fifteen (15) minute intervals. 8. The designer shall perform an analysis of the initial traffic data. a. Develop up to three (3) timing plans per intersection to be placed into the database at system startup. Traffic signal timings and offsets shall be optimized through the utilization of currently available computer based software. b. Develop traffic control parameters to be placed in the database to allow the system to select the designated timing plan based on a time-of-day/day-of-week schedule. 9. The designer shall provide services in accordance with the procedures of the Office of Community Involvement as required. 10. Traffic Control Data Base Preparation The designer shall analyze the traffic data collected by the system during the observation period of construction and develop final traffic signal timing and patterns. The designer shall develop two (2) AM peak plans, two (2) PM peak plans, three (3) off peak plans, and two (2) weekend plans including traffic responsive parameters to allow the system to select each plan. 11. Traffic Data Verification: a. The designer shall verify the data being reported by the system by manual measurement of the free flow traffic speed on each link along the traffic control network. b. To fine tune the system, the designer shall verify the volume data reported by the system by manual counts on each link in the traffic control network. c. The designer shall prepare a before and after evaluation report which evaluates the effectiveness of the new traffic control system. 12. Data Base Preparation ( after study): a. The designer shall prepare the data base that is updated during the observation 16.4-2
period as required for the fully operational system. b. After the system has been fine tuned, the designer shall conduct an after speed study similar to the before study conducted in the initial data collection (Step 7). c. The designer shall compare the results and project the travel time saving and all quality benefits. Plans and Specifications 1. Prepare plans and specifications for a computerized system as described in the System Definition Report and approved by the Department. 2. The plans and specifications shall include all necessary hardware and software for a completely operational system. 3. The plans shall include the installation of Variable Message Signs, Highway Advisory Radio, Closed Circuit Television, and Control Center modifications to comply with the requirements of the system design. 4. The plans shall include the installation of loop detectors for the monitoring of side street queuing. 5. The plans shall include any modification to existing signalized intersections necessary because of overhead utility conflicts and/or non-compliance with the Manual on Uniform Traffic Control Devices. 6. The designer shall prepare the following plans: a. 1:1000 scale plans of the communications conduit layout and location of all ITS devices b. System block diagram c. Traffic signal plans and local ITS facilities on 1:300 scale d. Fiber optic cable wiring diagram e. Construction details f. Electric service locations Construction Engineering 1. Review shop drawings. 16.4-3
2. Witness the testing of the base traffic control systems software working in conjunction with the signalized intersections and traffic detection sites. 3. Witness the testing of all systems software and traffic control software with all modes of operation. 4. Witness the testing of all component equipment at the site. 5. Review all test procedures and test results. 6. Provide assistance in the inspection of field, central and remote hardware at various stages of construction. 16.4-4