Preliminary Evaluation of the Proposed Sae J2364 15-Second Rule for Accessibility of Route Navigation System Functions while Driving

Abstract

A test-track study was conducted to assess the diagnostic properties of SAE J2364, the so called 15-second rule. Ten (10) drivers between the ages of 55 and 69 completed tasks both in a parked vehicle (statically) and while driving (dynamically). They engaged in 15 different tasks, including various destination entry tasks, with four commercially available route guidance systems, manual cell phone dialing, manually tuning an after-market in-dash radio to specific AM and FM stations, and adjusting the HVAC controls in the test vehicle.

Simple linear regression models to predict dynamic task completion time from static task completion time revealed an R² = 0.39. A model to predict number of lane exceedences from static completion time had an R² = 0.27. A regression equation to predict lane exceedences from dynamic completion time had an R² = 0.43.

Classification performance of the 15-second rule was analyzed using criteria based on “degraded performance” defined as 2 or more drivers exhibiting 2 or more lane departures during task execution on the 7.5 mile test track. Where 2 or more drivers had static completion times of greater than approximately 15 seconds, the task would fail the test. In terms of True Positives, all route navigation system destination entry tasks that required visual-manual methods both failed the 15-second rule and were associated with disrupted lanekeeping. In terms of False Negatives, tuning the Clarion after-market radio took less than about 15 seconds for static completion yet was associated with above-threshold disruptions of lanekeeping on the test track. In terms of True Negatives, the HVAC adjustment was the only task which was both completed in less than 15 seconds statically and had no appreciable effect on lanekeeping during the test track trials. Finally, five of the 15 tasks took longer than 15 seconds to complete in a parked vehicle (i.e., statically) yet were not associated with significant disruptions in lanekeeping on the test track.

The results of this preliminary assessment suggest that the 15-second rule, as implemented, has diagnostic sensitivity close to chance guessing. It identified most, though not all, demanding interactions at the expense of numerous false positives. These preliminary findings, together with the observation that the 15-second rule is, in itself, not diagnostic with regard to the locus of a driver distraction effects, suggest that opportunities for improvement or enhancement should be pursued. Recommendations are discussed.