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U of MNUniversity of Minnesota
Center for Transportation Studies

CICAS Stop Sign Assist (SSA) System

Principal Investigator:

Max Donath, Professor, Mechanical Engineering


Project Summary:

The University of Minnesota is nearing completion of the Intersection Decision Support (IDS) project. Project results include: 1) An analysis of rural expressway intersection crashes in Minnesota, including the development of a technique to identify intersections having crash rates higher than expected; 2) A statistical model which can be used to estimate or project the societal benefits of deploying a rural stop sign assistant at rural intersections; 3) The design, development, and implementation of a comprehensive rural intersection surveillance and data acquisition system. Gap acceptance behavior of drivers at a live intersection has been quantified, and two crashes have been captured; and 4) A task analysis, design study, and simulator-based evaluation of innovative Driver-Infrastructure Interface (DII) concepts, leading to an understanding of the timing and content of information needed for an effective, acceptable DII.

Proposed herein is the logical extension of the IDS project: a five year effort culminating in a Field Operational Test (FOT) performed at the Minnesota Test Intersection located at US 52 and County State Aid Highway 9 (CSAH 9) in Goodhue County, MN. This follow-on to the IDS project is separated into two components: a three-year, pre-FOT effort to finalize the design of the DII, and a two-year FOT under which the safety benefits and driver acceptance of the system can be validated. This program will investigate the integration of a cooperative element into the IDS system. Under the IDS program, no vehicle or driver information was delivered from the vehicle to the infrastructure. The infrastructure, however, did estimate vehicle classification using a laser-scanner based system. This system was used to determine differences in gap accepted as a function of vehicle length, height, and profile, and to test the hypothesis that larger vehicles require larger gaps. This project, however, will leverage resources emerging from the US DOT VII (Vehicle-Infrastructure Integration) Initiative. Under VII, a communication mechanism between vehicles and the infrastructure is emerging which will facilitate the efficient transfer of relevant data between the two. This capability will be exploited in the effort described here.

The pre-FOT work is complete, and a proposal to carry out the FOT has been submitted, through MnDOT, to the FHWA. The FHWA posed question to Minnesota, and answers to those questions will soon be submitted to the FHWA. If the FOT is approved, it is expected that the FOT will begin in the November-December time frame.

Two intersections were added to support the FOT: US 169 and CSAH 11 and MN TH 23 and County 7 in Marshall, MN. Both intersections are now up and running.


Project Details:

Reports or Products:

Related Links:

Minnesota researchers add their expertise to federal intersection safety initiative The Sensor, Spring 2007

Minnesota researchers join Cooperative Intersection Collision Avoidance Initiative 2007 ITS Institute News

Intersection Decision Support: Reducing crashes at rural intersections The Sensor, Fall 2003