Effects of using a portable navigation system and paper map in real driving

Research design/methodology

TYPE:  Quantitative evaluation employing a 2 x 2 mixed factorial research design with the following factors: 

• navigation tool (PNS versus paper map) as the between-subjects factor
• driving environment (urban versus rural settings) as the within-subjects factor

The outcome measures were defined in terms of driving performance and efficiency as outlined below.

• Driving performance measures included the following:
  
  • average speed (km/h) and its standard deviation
    
  • variance in longitudinal and lateral acceleration (g)
  • mean yaw rate (degrees/sec) and its standard deviation
    
  • driving pass through distance (m)
• Driving efficiency measures included the following:
  
  • trip duration (s)
  • trip distance (m)

Research question

To determine whether driver performance and efficiency is improved when using a portable navigation device as compared to a paper map in real driving environments.

Intervention

Two groups were compared: 

• Group 1 was asked to follow the PNSs (Mio-tech A700) route guidance information after the predetermined starting point and destination were programmed into the unit. 
• Group 2 received the starting point and destination marked on a detailed paper map (60 cm x 45 cm at 1:20,000 scale) and was allowed an unspecified amount of time to plan their route.  Group 2 drivers were able to refer to the printed map whilst en route.

Outcome

HIGHLIGHTS:

Driving Efficiency

• Trip duration was shorter for PNS versus paper map for urban (606.6 s vs. 703.4 s) and rural driving (739.9 s vs. 794.1 s)
• Trip distance was shorter for PNS versus paper map for urban (6276.5 m vs. 6734.7 m) and rural driving (10388.0 m vs. 10588.0 m)

Driving Performance

• Average speed was statistically significantly faster for PNS versus paper map for urban (37.5 km/h vs. 34.8 km/h) and rural driving (50.8 km/h vs. 48.2 km/h)
• PNS users had a statistically significantly better average yaw rate and standard deviation versus paper map users  (The yaw rate and its standard deviation were the main performance measures for vehicle control.)
• However, statistical significance was not observed between the navigation tools for comparisons of the standard deviation of mean speed, variance in lateral acceleration and variance in longitudinal acceleration.

IMPLICATIONS: Drivers using PNSs appear to have an advantage over users of paper maps in regards to the following: 

• Driving efficiency - PNS drivers required less time to go shorter distances with fewer course corrections in both urban and rural environments  
• Driving performance - PNS drivers exhibited better car stability and control

Therefore, using PNSs may lead to potentially safer driving and may offer savings in gas and time.

Further areas for research

Future research may draw comparisons among portable navigation systems with various advanced features such as 3-D street level rendering, real-time traffic updates and heads-up displays.