Connected Vehicle Enabled Freeway Merge Management – Field Test
Brian L. Smith, PE
The act of merging (on freeways, roundabouts, etc.) creates vehicular conflicts that frequently result in congestion and crashes. Connected vehicles present a unique opportunity to develop a dynamic assistance system by utilizing the newly available vehicle trajectory data and capability of relaying advisory messages to vehicles in the system. With this background, the research team has previously developed three freeway merge assistance algorithms (lane-level variable speed limit, lane changing advisory, and merge control) for FHWA. This project will build upon the prior work and conduct a field test of these algorithms at the Smart Road of the Connected Vehicle UTC testbeds. Results from this field testing will provide real understanding on how these types of merge assistance algorithms can be tested and/or implemented in a real situation.
Task 1: Preparation of Field Testing
- Algorithm Refinement
Refine merge management algorithms, i.e. VSL, LCA and MCA, to prepare for field implementation. This task will simplify the current algorithms so that they can be readily adopted for software development for field testing.
- Development of Field Testing Settings
a. Prepare necessary settings and parameters for field testing each of three
b. Include a simplified concept of operations
Task 2: System Development and Implementation
- Software Development
Develop Software for each of the algorithms developed by CTS team. The application development consists two parts: a) OBE application and b) RSE application. For the RSE there will be three different applications for the three different algorithms VSL, LCA and MCA. The OBE applications will be developed so that they can communicate with the RSE applications, receive advisory from the RSE and implement partial control according to advisory provided by the RSE applications. For example, in the case of the Merging Control algorithm (MCA) the OBE application will implement the control strategy selected by the RSE application.
- System Implementation
a. Implement the developed applications to both RSE and OBE In this stage the developed OBE and RSE applications will be integrated with the OBE and RSE hardware.. RSEs will contain only one RSE application since at an instance only one algorithm will be implemented for field test. All the test-vehicles will be equipped with OBE applications.
b. Include rigorous testing of the integrated system before field testing.
Task 3: Field Testing
- Field Preparation
a. The field testing will be conducted at the Smart Road facility in Blacksburg given
the ability to fully control test conditions.
b. For evaluation of the algorithms developed it will be necessary to have merging sections similar to the simulation model developed by the UVA CTS research team and which was used for evaluation for the algorithms in the simulated environment in VISSIM. Depending on the existing lane configuration at the Test Bed facility, sections of the roadway can be converted temporarily with different traffic operational tools to create merging areas that can be representative of any freeway merge areas. For example using traffic cones mock merging sections can be created.
- Field Testing
a. After the development of RSE and OBE applications and the Software-hardware integration a step by step feasibility study will conducted to refine the applications developed to test functionality of the overall system. This phase will be conducted on the Smart Road facility since it provides a fully controlled environment which is necessary for integration and testing. At this phase the three proposed algorithms will be tested in the field successively in the following order: (i) Lane- Level variable speed limit, (ii) Lane Changing Algorithm and (iii) Merging Control Algorithm.
Task 4: Data Collection and Analysis of Field Testing Results
- Data Collection
a. After the experimental setup, for each of the algorithm detailed individual vehicular data in merging lane and mainline will be collected. Each of the test vehicles will be given unique identification number. The collected data will include precise vehicle location, speed, acceleration, vehicle type, vehicle length. Besides these general vehicle data it is central to this experiment to collect data on number of lane changes and gap acceptance. For the detailed data collection the data acquisition installed in the test-vehicles will be utilized.
- Analysis of Field Testing Results
- Refinement of System
a. Based on the analysis and results of the Smart Road field testing, further
refinement of the algorithms will be done.
b. Refine UVA CTS connected vehicle simulation environment. c. Identify the limitations of the overall study and define future research
Task 5: Final Report
A final report will be prepared which will include detailed description of the project, methodology, data analysis and results