Traffic Analysis Tools Volume IX: Work Zone Modeling and Simulation
A Guide for Analysts
New Jersey Turnpike Authority and Rutgers University New Jersey Lane Closure Application[9]
Overview
The New Jersey Turnpike Authority, consisting of both the New Jersey Turnpike (150 miles) and Garden State Parkway (180 miles), funded the development of a modeling application that provides operations managers and engineers with information regarding queue and delays resulting from lane closure events. The tool, known as the Rutgers Interactive Lane Closure Application or RILCA is GIS-based and was developed by the Rutgers University Intelligent Transportation System Laboratory. The impetus for the development of tool was, in part, to put into electronic format hard-copy versions of traffic volume tables that operation managers would reference in order to approve or disapprove maintenance and contractor applications for lane closures related to roadway maintenance (guardrail repair, sign repair, etc.).
The lane closure tool was developed using the ArcGIS software package as the main development environment. Included in the GIS database is detailed geometric data for all of the roadway links for both the New Jersey Turnpike and Garden State Parkway including surrounding highways and local streets. Now, the RICLA tool provides operations managers, supervisors and engineers with the following features:
- Traffic Demand — Volume information on selected links at a given time period on any given date.
- Roadway Data — Link characteristics including number of lanes, AADT, milepost and link length.
- Lane Closure Schedule — A function that generates lane closure schedule for selected links based upon hourly volume data processed by the Rutgers Intelligent Transportation Systems (RITS) team.
- Visualization — A simple visualization function that shows the extent of expected queuing and delays as a result of lane closure and spill back onto upstream links in the form of link colors.
- Cost Impact — Integrated lane closure cost estimation function.
Today, two versions of the tool currently exist: one for the New Jersey Turnpike (called the Rutgers Interactive Lane Closure Application or RILCA) and one for the Garden State Parkway (called the Parkway Operations Lane Closure Application or POLCA). A third version is being developed for the New Jersey Department of Transportation.
Applications
The following applications are available in both RILCA and POLCA
- Lane Closure Schedule — A schedule for the minimum number of lanes to be open on a roadway section can be generated. These schedules are generated using the Annual Average Daily Traffic (AADT) data for the selected day. Lane closure schedules can be generated for a selected day or a week starting with a selected day for each month. An annual percentage increase in traffic can also be entered as an input to obtain the schedules for the future traffic demand.
- Lane Closure Info — The Lane Closure Info option is used to generate estimates of user delay and queuing resulting from a particular lane closure scenario. Outputs include Level of Service (based on the HCM procedure for work zone studies), minimum number of lanes to be open, hourly number of vehicles in queue, average hourly delay per vehicle, total hourly delay, and queue length.
- Incident Analysis — The Incident Analysis option is used to generate delays and queues resulting from an incident. It operates in similar fashion to the Lane Closure Function but includes the two additional outputs of time of maximum queue length and time of queue clearance.
The New Jersey Turnpike Authority has not developed any specific polices or procedures regarding the use of the lane closure application tool. Currently, users of the tool are advised to use the results of the analysis as just one piece of the overall analysis and to also consider personal experience with lane closures and previous examples comparing estimated values to actual values.
Data
Data for the lane closure applications are routinely updated but are quite different for each version of the tool. For the RILCA version, hourly traffic volume data is generated from a combination of roadway sensor data and electronic toll collection (ETC) tag data. These data are combined to generate hourly traffic volume data which is entered into the GIS database every two months.
The POLCA version also use ETC tag data but this data is not as accurate as the New Jersey Turnpike since users only pay when they enter the parkway. The ETC tag data is combined with toll plaza hourly factors to estimate hourly traffic volumes for roadway links. These data are updated monthly, but the data is three months old due to the amount of processing.
[9] This case study references the Rutgers Interactive Lane Closure for Work Zone Planning Manual prepared by the Rutgers University Intelligent Transportation Systems Laboratory (November 2007 edition).
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