Developing and Testing Operational Definitions for Functional and Higher Order Driving Instruction

The amount and type of driving instruction provided to novice teen drivers during the learner period may be associated with future crash risk. The purpose of this study was to (1) operationally define two types of driving instruction: functional and higher order instruction, and to (2) test these definitions in a sample of newly licensed novice teenage drivers during the first ten hours of supervised driving. Functional driving instruction was defined as instruction that relates to the present time or immediate future; and related to specific events that are occurring during the drive itself. Higher order driving instruction was instruction that could be extrapolated to a future driving situation; that conveys general principles of driving related to potential events that occur. These operational definitions were tested in conversation occurring during driving instruction in a sample of 90 teen drivers, recruited within three weeks of receiving their learner permit. Teen drivers’ vehicles were equipped with microphones; conversations were recorded and coded for each type of instruction that was observed. As expected, parents provided substantial driving-related instruction on a variety of topics. During the first ten hours of supervised driving only 17.5% of observed driving-related instructions was higher order. This test provides face validity of the operational definitions of driving instruction. These definitions may assist in quantifying the type and amount of driving instruction occurring during the supervised practice stage of licensure, and provide an empirical basis for evaluating the association between driving instruction and independent driving performance

Measuring Young Drivers’ Behaviors during Complex Driving Situations

Driving behaviors of teenagers and adults in complex driving situations, viz., merges and intersections, from an 18-month longitudinal naturalistic driving study were analyzed. Variables from multiple sources were selected to create an Unsafe Driving Index to rate drivers’ behaviors in these locations. Teenagers scored lower on this index, corresponding to safer driving behaviors, than adults. However, the teenagers’ scores for the index increased across the study period. The interpretations of these findings are discussed with respect to the methodological aspects of the study and in terms of driver training and rule following

Validity of the C-RDS Self-Reported Risky Driving Measure

This study examined the reliability and validity of the Checkpoints Risky Driving Scale (C-RDS) in relation to the Dula Dangerous Driving Index (DDDI) and an objective measure of risky driving. Naturalistic and survey data were collected over an 18-month period from 42 newly-licensed teenage drivers. Kinematic Risky Driving was operationally defined as the rate of elevated gravitational-force events per 100 miles obtained from accelerometers and global positioning systems. Two self-report measures of risky driving, the C-RDS and the DDDI, were assessed at 6-months, 12-months, and 18-months after licensure. Reliability was examined for each measure with correlations and autoregressive models over three time points. Validity was assessed by correlations between the measures and cross-lagged autoregressive models of the longitudinal association of self-reported measures with Kinematic Risky Driving and vice versa. Both the C-RDS and DDDI measures demonstrated substantial stability over time and were highly correlated with each other. The C-RDS measure was significantly associated with Kinematic Risky Driving. The findings provide evidence for the reliability and validity of C-RDS

Evaluation Tools for Low-Speed Automated Vehicle (LSAV) Transit Readiness of the Area

69A3551747115/Project 05-113Automated shuttles are small, low-speed (generally less than 25 mph) vehicles that do not require a human operator, though to date all have included an onboard human attendant. This project aims to assess the limitations that the EasyMile EZ10 Gen 3 low-speed automated vehicle (LSAV) encountered while operating on public roadways. The primary interests are to evaluate the infrastructure elements that posed the most challenges for the LSAV during its deployment. Further, the EasyMile EZ10 Gen 3 is advertised as being capable of operating at SAE International Level 4 Automated Driving System capability in certain ODDs. Accordingly, the team deployed the LSAV with the expectation that it would be operated at SAE Level 2 capability. The human safety operator was required to intervene in scenarios beyond the vehicle\u2019s automated functional capability. The results of this analysis indicated that the LSAV operated at a lower than expected speed, experienced a high frequency of disengagements, and had a regular need for safety operator intervention. These results suggest that the EZ10 Gen 3 vehicle is not yet operating at SAE International Level 4 capability on routes with moderate complexity

Changes over 12 months in eye glances during secondary task engagement among novice drivers

During their first year of driving, crash rates among novice drivers are very high but decline rapidly. However, it is not clear what skills or knowledge they are acquiring in this period. Secondary task engagement while driving is a contributing factor to many traffic collisions and some of the elevated crash risk among novices could be explained by greater prevalence or longer periods of eyes off the road while engaging in these non-driving tasks. The current study looked at the eye glances of novice teen drivers engaging in secondary tasks on a test track at 0 and 12 months of licensure and compared their performance with their parents. Novices improved from 0 to 12 months on their longest single glance off the forward roadway and total percentage of time for eyes off the forward roadway, but parents remained stable. Compared with their parents, the longest single glance off the forward roadway was longer for novices at 0 months, but by 12 months there was no difference between the groups. However, for total percentage of time for eyes off the forward roadway, novices performed the same as their parents at 0 months and actually had shorter times at 12 months. These findings could reflect the combined development of driving skills over 12 months and the relative experience that modern teenagers have with portable electronic devices. The results suggest that novice drivers are particularly poor at engaging with secondary tasks while driving