Excess Fuel Consumption Due to Selection of a Lower Than Optimal Gear—Case Study Based on Data Obtained in Real Traffic Conditions

Appropriate driving technique, in compliance with eco-driving principles, remains an effective method to reduce fuel consumption. The selection of the correct gear is one of the pertinent factors when driving a car with a manual gearbox. In this study we have analyzed fuel overconsumption based on data recorded in real traffic conditions for vehicles driven by experienced drivers, using a black-box model. It was found that the total share of trip time with a lower than optimal gear selected amounted to from c.a. 3% for motorway driving up to 28% on rural roads. The mean fuel consumption reduction factor (following selection of the next gear up) amounted to from c.a. 2% up to 20%, depending on the selected gear and type of driving. Unfortunately, the potential for reduction of fuel consumption is not evenly distributed over the entire operating area of the engine. Thus, the cumulative reduction of fuel consumption, due to selection of the optimal gear, amounted to from c.a. 0.2% for motorway driving up to 3–6%, for urban and rural driving. It was shown that due to the selection of the appropriate gear, there still exists a real possibility of reduction of fuel consumption, even in the case of experienced drivers.

Driving Characteristics of Older Drivers and Their Relationship to the Useful Field of View Test

Background: To maintain the mobility of older people in later life, it is essential to sustain their autonomy; however, driving is a complex task, requiring a large range of visual, psychomotor and cognitive abilities. Subsequently, a key issue is to measure and evaluate the fitness to drive of older drivers. Several methods have been proposed, among them the useful field of view (UFOV) test. Objective: The present study aimed to identify driving characteristics in older drivers and the relationship between the UFOV test and the on-road driving results. Method: A total of 80 drivers aged 70 years or older performed both the UFOV test and the on-road driving assessment. The ‘B On-Road' (Behaviour On-Road) protocol was used for the fitness-to-drive assessment. Results: ‘Driving too fast' was the item reported most often during the on-road assessment, followed by problems with the manual gearbox and ‘attention to signs, road lines and traffic lights'. Overall, the results showed that the older the driver, the more errors were reported during the on-road driving assessment, as well as the slower the performance on the UFOV test. A significant relationship between the total number of on-road errors, as measured by the B On-Road protocol, and the UFOV 3, which stresses the capacity of selective attention, was found. Conclusion: The recommendation is still to use on-road driving assessment to fully assess fitness to drive for older drivers whose ability to drive requires assessment. However, to supplement this, the UFOV test, in particular the UFOV 3, is a valuable complement in selecting those drivers requiring to be assessed.