Juha Luoma

Effects of retroreflector positioning on nighttime recognition of pedestrians

This field study investigated potential effects of retroreflector positioning on recognition of nighttime pedestrians. The subjects task was to press a response button whenever he/she recognized a pedestrian on or alongside the road, while in a car with low-beam lamps on that was driven at a constant speed on a dark road. The results showed that each retroreflector configuration yielded significantly longer recognition distances than the no-retroreflector configuration. More importantly, the retroreflective markings attached to the limbs led to significantly longer (about 60-80%) recognition distances than when the retroreflective markings were attached to the torso. Furthermore, a pedestrian was more recognizable while crossing the road than while approaching the subject vehicle, except for configurations involving no retroreflective markings.

Effects of variable message signs for slippery road conditions on reported driver behaviour

A field study by Rama and Kulmala (Rama, P., Kulmala, R. (2000). Effects of variable message signs for slippery road conditions on driving speed and headways. Transportation Research, Part F, 3, 85–94.) showed that a variable message sign warning about slippery road conditions reduced the mean speed by 1–2 km/h. The study also showed that a variable message sign recommending a minimum headway between vehicles decreased the proportion of short headways. However, the signs may have other effects on driver behaviour besides those measurable in terms of speed and headway, and this study was designed to investigate such potential effects. In total, 114 drivers who had encountered the slippery road condition sign and 111 drivers who had encountered the sign showing recommended minimum headway in adverse road surface conditions were interviewed. The results suggested that these variable message signs do indeed have other effects, such as the refocusing of attention to seek cues on potential hazards, testing the slipperiness of the road, and more careful passing behaviour. On the other hand, the results suggested that driving speed and headway are essential variables with which many other variables correlate.

Effects of experience with retroreflectors on recognition of nighttime pedestrians: comparison of driver performance in Finland and Michigan

Abstract This field study replicated a recent experiment by Luoma, Schumann and Traube [(1996) Effects of retroreflector positioning on nighttime recognition of pedestrians. Accident Analysis and Prevention, 28, 377-383.] on the effects of retroreflector positioning on nighttime recognition of pedestrians. The key difference between the two studies was that Finnish drivers who have substantial experience with different pedestrian retroreflectors were used in the present study, while Michigan drivers—whose experience with pedestrian retroreflectors is more limited—were used in the previous study. The subject’s task was to press a response button whenever he recognized a pedestrian on or alongside the road, while in a car, with low-beam lamps on, that was driven on a dark road. The results showed that the main effects were the same as found in the previous study. Specifically, the retroreflective markings attached to the limbs led to significantly longer recognition distances than when the retroreflective markings were attached to the torso, and a pedestrian was more recognizable while crossing the road than while approaching the subject vehicle. However, the differences between the recognition distances produced by the various retroreflector configurations were smaller in Finland than in Michigan, and the Finnish subjects more frequently responded incorrectly.

Main characteristics of train–pedestrian fatalities on Finnish railroads

The aim of this study was to describe the frequency of fatalities, timing of collisions and characteristics of persons killed in train-pedestrian collisions on Finnish railways during 2005-2009. In addition, the Finnish results were compared with those collected in Sweden. The Finnish data were combined from five different sources. The results showed that 311 pedestrians were killed in train-pedestrian collisions, including 264 suicides, 35 accidents and 12 unclassified events. For each event type, most of the victims were male. Most suicide victims were in the 20-29 year age group and on average younger than people who chose some other form of suicide. About half of all victims were intoxicated by alcohol, medicines and/or drugs. Both suicides and accidents occurred most often at the end of the week but no specific peak for time of year was found. Suicides occurred most frequently from afternoon to night and accidents during the rush hours. Most train-pedestrian fatalities happened in densely populated areas. In conclusion, the effective prevention of railway suicides and accidents calls for a systems approach involving effective measures introduced by authorities responsible for urban planning, railways, education and public health.

Effect of three countermeasures against the illegal crossing of railway tracks

This study was designed to investigate the effects of three countermeasures--landscaping, building a fence and prohibitive signs--on the frequency of trespassing, which in this case means crossing the track at places where it is forbidden. At each location the official route was no more than 300 m away. The main results showed that the effect of each countermeasure on the frequency of trespassing was statistically significant. Specifically, the fencing reduced trespassing by 94.6%, followed by landscaping (91.3%) and prohibitive signs (30.7%). The majority of illegal crossings were committed alone and the persons trespassing were mostly adults and men. In addition, the results demonstrated some tendencies of how the effects of the selected countermeasures can vary with the characteristics of the trespassers. The main implication of this study is that the building of physical barriers such as landscaping or fencing is recommended for reducing trespassing. However, if the required resources are not available or the site is not suitable for such measures, the use of prohibitive signs is recommended. Further, there is a need to tailor the countermeasures to the characteristics of the trespassers in order to ensure that the most appropriate countermeasures are applied.

Effects of turn-signal colour on reaction times to brake signals

This laboratory experiment was designed to compare reaction times to brake signals when they appear with red or yellow turn signals. The subjects task was to respond as quickly as possible to the onset of peripherally presented brake lamps, while engaged in a central tracking task. There were three lamp conditions: brake lamps alone, brake lamps while turn signal was on, and a turn-signal lamp alone. The results showed that yellow turn signals, in comparison to red turn signals, led to significantly shorter reaction times to brake signals.

EFFECTS OF NONPLANAR DRIVER-SIDE MIRRORS ON LANE CHANGE CRASHES

In this quasi-experiment, we investigate the effects on lane-change crashes of nonplanar (spherical convex and multiradius) driver-side mirrors compared to planar mirrors. The analysis was based on 1,062 crashes reported from 1987 to 1998 to Finnish insurance companies for vehicles with passenger-side spherical convex mirrors and one of three types of driver-side mirror (planar, spherical convex, or multiradius). The results show that the mean effect of nonplanar mirrors compared to planar mirrors was a statistically significant decrease of 22.9% in lane-change crashes to the driver side. The effects of spherical convex and multiradius mirrors were not statistically different from each other. The nonplanar mirrors were beneficial especially for the high-risk driver groups, as well as for the lane-change situations and environmental conditions in which most lane-change crashes take place in the United States. These findings support the use of nonplanar driver-side mirrors. If drivers have problems with jud...

Effects of driver-side mirror type on lane-change accidents

This quasi-experiment was designed to investigate the effects of the type of driver-side mirror on lane-change accidents. The analysis was based on 407 accidents reported from 1987 to 1992 to Finnish insurance companies, for vehicles with passenger-side convex mirrors and one of three types of driver-side mirrors (flat, convex or multiradius). The results showed that there was no difference between the multiradius and convex mirrors in the frequencies of lane-change accidents to the left. Compared to the flat mirror, the mean effect of the multiradius and convex mirror was a 22% decrease. However, the statistical strength of the data was low; 95% confidence interval ranged from a 51% decrease to a 25% increase. This result was not related to driver characteristics or driving conditions. In conclusion, the multiradius and convex driver-side mirrors, in comparison to the flat mirror, are more likely to reduce than increase lane-change accidents. A theoretical implication of this study is that minimizing the...

Does facing traffic improve pedestrian safety

This study was designed to evaluate the potential safety importance of the walking direction along a road by examining pedestrian accidents as a function of exposure to risk. The study was limited to rural two-lane roads with no pavement or pedestrian lane. The accident data included police-reported road accidents from Finland between 2006 and 2010 in which a motorized vehicle had struck a pedestrian walking along the road. There were 18 accidents involving a fatally injured pedestrian and 87 accidents involving a non-fatally injured pedestrian. The exposure data collected from the roughly 3400km included 258 pedestrians. The main finding was that the mean effect of facing traffic compared to walking with traffic was a 77% decrease in fatal and in non-fatal injury pedestrian accidents. The results further showed that the effects were greater for main roads than for secondary roads. The main implication of this study is that information about the importance of facing traffic should be reinforced with specific information about its substantial safety benefits.

Driver Acceptance of Weather-Controlled Road Signs and Displays

This study was designed to investigate driver acceptance of the weather-controlled road signs and displays on Finland’s southern coast where road condition changes are particularly frequent and rapid. There were 36 variable speed limit signs and five variable message displays to warn about hazardous conditions on the 14-km-long experimental road section. Local weather and road surface conditions were monitored automatically from road weather stations; the information gathered was used for determining appropriate speed limit, as well as for controlling variable slippery road signs and temperature displays. Five hundred ninety drivers were interviewed 3, 4, 11, and 13 months after the introduction of this new road section. The results showed that drivers recalled the variable signs very well. Furthermore, 81 percent of the drivers said that the posted speed limit was appropriate, and 95 percent of the drivers stated that the variable speed limits were useful. However, only a relatively small proportion of drivers estimated that the slippery road sign or temperature display influenced their behavior. The main implication of this study is that the concept of the weather-controlled road signs and displays is a promising one. However, objective data will be collected in order to estimate the effects of the weather-controlled road signs and displays on driver behavior and to evaluate the profitability of the system.