Drivers’ impressions under high-pressure sodium and LED street lighting

Abstract

In order to compare drivers’ subjective impressions when exposed to high-pressure sodium versus LED street lighting, an experiment was conducted on a Belgrade street. All general requirements for an adequate comparison of subjective impressions, equal luminances being the most important, were fulfilled. A survey was conducted using a questionnaire, which the respondents filled out immediately after driving through both zones of the illuminated street. The respondents, who were young drivers (students), aged 20–25 years, were asked to select the more appropriate of the two installations regarding seven lighting parameters as well as giving their overall impression. The two regimes for which the survey was done gave opposite results. In the normal regime, where both installations had the same photopic luminance, the LED installation was evaluated as a better solution by a majority of the respondents for most of the analysed parameters. In the mesopic regime, where both installations had the same mesopic luminance, most of the respondents judged that the high-pressure sodium installation was the better choice.

Drivers’ Preference for the Color of LED Street Lighting

“…The driving speed was agreed to be around 50 km/h (31 mph), corresponding to the most frequent limit in city streets. Contrary to the pilot project presented in Djokic et al [22], the part of the street in which the survey took place was not closed for vehicle traffic. However, due to the location of the case street (commercial zone) and time of day, traffic density was very low.…”

“…The questionnaire used in Djokic et al [22] served as an initial questionnaire for the survey. It was finalized by the focus group that consisted of five authors of this paper, their colleagues from the academic community (four) and experienced street lighting designers (six).…”

“…It is interesting that Djokic et al [22], comparing street lighting installations realized with HPS lamps (CCT = 2000 K) and the 4000 K LEDs, found that most of the respondents preferred the color appearance of the 4000 K LEDs. However, the respondents participating in the present survey found that the color appearance of the 3000 K LEDs was more appropriate than that of the 4000 K LEDs.…”

“…The former included two surveys based on detection of small targets and pedestrians, and the latter a survey with actual driving. To the best of our knowledge, surveys investigating the drivers' subjective impressions by involving actual driving are very rare [22]- [24]. Although there was research showing that the driver's behavior on the street is similar to that in a driving simulator (this conclusion was reached considering various hazardous scenarios) [25], the authors do not consider that driving simulators can replace actual driving when analyzing the influence of color of light on driving performance.…”

Investigation and Feasibility Evaluation of Using Nanogrid Technology Integrated Into Road Lighting System

“…LED technologies are the next generation of energy-efficient lighting solutions for road lighting systems. Several research articles [3]- [6], [30]- [31] discuss efficiency, visibility, traffic flow, safety, environmental, and economic matters comparing HPS luminaires to LED luminaires. Both HPS and LED luminaires have similar levels of life-cycle environmental impact, as highlighted in [3].…”