SAFETY EFFECTS OF ADAPTIVE CRUISE CONTROLS IN CRITICAL TRAFFIC SITUATIONS

Conventional cruise controls (CC) are capable of keeping a constant speed, but the driver has to intervene and control the speed manually when speed change is required. Adapted cruise controls (ACC) are developed to extend the speed keeping function by automatic distance keeping. Expected advantages are reduced workload and rear-end collisions, increased driver comfort, and traffic smoothness. As ACCs are designed as driver comfort systems, their braking power is limited to 0.2 to 0.3 g. Also, ACCs do not consider stationary objects. Finally, the automatic distance control is only performed within a limited speed interval. Ten drivers drove with ACC and ten without ACC in a VTI simulator. They were exposed to traffic situations where the ACC limitations may be critical. Acceptance, driver performance, and workload were studied. ACC drivers approaching a stationary queue started to brake later and braked harder than those driving manually. Four crashed into the rear end of the queue, compared to one driver in the control group. When preceding cars braked hard or pulled out, ACC-initiated braking and warnings resulted in longer headways. The ACC was well accepted and did not influence the workload level. Conclusions were that: 1) safety may be negatively influenced; 2) drivers may expect more from ACCs than they can provide, and when necessary react later and more abruptly than during manual driving; and 3) early system actions and warning may reduce criticality, if the target is detected.

• Supplemental Notes:
  • Five volumes of papers and one volume of abstracts comprise the published set of conference materials.
• Corporate Authors:

  VERTIS

  TORANOMOM 34 MORI BUILDING 1-25-5
  TORANOMON, MINATOKU, TOKYO 105  Japan 
• Authors:
  • NILSSON, L
• Conference:
  • Steps Forward. Intelligent Transport Systems World Congress
  • Location: Yokohama, Japan
  • Date: 1995-11-9 to 1995-11-11
• Publication Date: 1995-11

Language

• English

Media Info

• Pagination: p. 1257

Subject/Index Terms

• TRT Terms: Adaptive control; Cruise control; Driver performance; Drivers; Intelligent transportation systems; Nuclear reactors; Personnel performance; Research; Safety; Traffic characteristics
• Geographic Terms: Sweden
• Old TRIS Terms: Criticality; Safety research
• Subject Areas: Highways; Operations and Traffic Management; Research; Safety and Human Factors; Vehicles and Equipment; I91: Vehicle Design and Safety;

Filing Info

• Accession Number: 00722070
• Record Type: Publication
• Report/Paper Numbers: Volume 3
• Files: TRIS
• Created Date: Jun 27 1996 12:00AM