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PubMedDate not supplied

[Prevalence of mobile phone use while driving vehicles].

OBJECTIVE: To estimate the prevalence of mobile telephone use while driving vehicles in the city of Lleida (Spain). METHODS: A random sample of 1536 cars passing through six intersections regulated by traffic lights in Lleida were selected (three with urban traffic and three with interurban traffic). Cyclists, motorcyclists and driving school cars were excluded. The variables studied were mobile telephone use, age, (18-40; 41-60; >61), sex, the presence of passengers, type of intersection (urban traffic/interurban traffic), day of the week (working day/weekend or holiday) and hour of the day (rush hour/non-rush hour). The prevalence of mobile telephone use was calculated in percentages with a 95% CI. The relationship among the dependent variable (mobile telephone use) and the other independent variables was studied using odds radios (OR) and 95% CI. RESULTS: A total of 1536 direct observations were made and mobile telephone use was detected in 50 drivers. The prevalence was 3.3 (95% CI, 2.4-4.3). The prevalence was higher in men (OR = 2.2; 95% CI, 1.0-5.7), in drivers aged more than 60 years old (OR = 2.2; 95% CI, 0.5-8,4) and in those aged 18-40 years old (OR =1.5; 95% CI, 0.8-3.0), in unaccompanied drivers (OR = 3.0; 95% CI, 1.5-6.3), in urban intersections (OR = 2.7; 95% CI, 1.2-5.9), on workdays (OR = 2.0; 95% CI, 0.9-4.4) and at the rush hour (OR =1.4; 95% CI, 0.8-2.4). CONCLUSIONS: The prevalence of mobile telephone use while driving vehicles can be considered high, because of the increase in car accidents. The profile of drivers using mobile telephones corresponds to men aged 18-40 years or more than 61 years, in urban intersections, without passengers, during workdays and at the rush hour. We recommend the implementation of measures to decrease the use of mobile telephones while driving.

Adolescent↗

PubMed2002

Effects of early environment on field CA3a pyramidal neuron morphology in the guinea-pig.

There is evidence that early environmental conditions have profound effects on the morphology of the dentate granule cells. The aim of the present study was to obtain information about the effects of early environment on neuron morphology in the hippocampal field CA3, a structure closely linked to the dentate gyrus. The dendritic trees and the somata of field CA3a pyramidal neurons were quantified in Golgi-stained brains of guinea-pigs of both sexes raised in either a social or an isolated environment. Two pyramidal neuron types were found in CA3a, characterized by either a long or a short shaft. Environment affected the apical tree of the long-shaft neurons only in males and that of the short-shaft neurons in both sexes. In isolated males the long-shaft neurons had a decrease in the number of dendritic intersections (62-82%), branching points (76%) and length (71%) in the middle third of the apical tree. The short-shaft neurons had a decrease in the number of intersections at two distal levels only in both isolated males (26, 83%) and females (77, 82%). The shaft spine density was affected by environment in the long-shaft neurons of males only, with a density increase (110%) in isolated males. In both sexes the basal tree of only the long-shaft neurons was affected by environment. Isolated males had a decrease in the number of dendritic intersections (65-88%), primary dendrites (80%) and dendritic length (88%) and isolated females had a decrease in the number of intersections (51-89%), branching points (77%) and dendritic length (85%). The soma major axis of only the long-shaft neurons was affected by environment with a reduction in isolated males (90%) but an increase in isolated females (111%). These results demonstrate dendritic atrophy of CA3a pyramidal neurons following early isolation and a different reactivity to environment of the two CA3a pyramidal neuron types, their apical and basal trees and the two sexes. The dendritic atrophy of CA3a neurons caused by isolation is likely to be associated with an impairment in the physiology of the hippocampal formation and in the forms of memory in which the hippocampal formation plays a major role.

Aging↗

PubMedDate not supplied

Ultrasound beam orientation during standard two-dimensional imaging: assessment by three-dimensional echocardiography.

Standard two-dimensional echocardiographic image planes are defined by anatomic landmarks and assumptions regarding their orientation when these landmarks are visualized. However, variations of anatomy and technique may invalidate these assumptions and thus limit reproducibility and accuracy of cardiac dimensions recorded from these views. To overcome this problem, we have developed a three-dimensional echocardiograph consisting of a real-time scanner, three-dimensional spatial locater, and personal computer. This system displays the line of intersection of a real-time image and an orthogonal reference image and may be used to assess actual image orientation during standardized two-dimensional imaging when the line-of-intersection display is not observed by the operator. Three hundred forty standard images were assessed from 85 examinations by 11 echocardiographers. Twenty-four percent of the unguided standard images were optimally positioned within +/- 5 mm and +/- 15 degrees of the standard. Of the optimal images, two thirds were parasternal long-axis views. A subsequent study with three-dimensional echocardiography and line-of-intersection guidance of image positioning showed 80% of the guided images to be optimally positioned, a threefold improvement (p < 0.001). Two-dimensional echocardiography does not achieve reasonably consistent optimal positioning of standard imaging views, suggesting that measurements taken from these views are likely to be suboptimal. Three-dimensional echocardiography that uses line-of-intersection guidance improves image positioning threefold and should therefore improve the accuracy and reproducibility of quantitative echocardiographic measurements derived from these images.

Adolescent↗

PubMed2005

Traffic as a source of organophosphorus flame retardants and plasticizers in snow.

Snow samples collected in northern Sweden at a road intersection and an airport indicated that traffic is a source of organophosphorus flame retardants and plasticizers (OPs) in the outdoor environment. Analysis of snow samples taken at distances of 2, 100, and 250 m from the road intersection showed that the total amount of OPs declined as distance increased. Of the 11 analyzed substances, tris-(2-chloroisopropyl) phosphate (TCPP) dominated in the snow samples from the intersection, with levels of 170, 130, and 110 ng/kg snow at distances of 2, 100, and 250 m. Similar amounts of TCPP were found at the airport (100-220 ng/kg). These levels are approximately twice as high as the level found in the reference snow sample from a remote area (70 ng/kg). A possible explanation for the higher levels of TCPP found close to the road intersection is that it may be emitted from the interior of cars via their ventilation systems. Triphenyl phosphate (TPP) was identified in lubricants and in waste oil from vehicles, and thus, leakage of transmission and motor oils is a probable source of TPP found at the sampled sites. Ten OPs were detected in the three samples from the airport, of which tributyl phosphate (TBP) was the most abundant, at levels 3 orders of magnitude higher than in the reference sample, that is, 25 000 compared to 19 ng/kg. The main source of TBP at the airport was traced to aircraft hydraulic fluid. Analysis of background air and deposition samples indicated that some OPs are subject to long-range air transportation.

Air Pollutants↗

PubMed2005

A study of binary adsorption of aromatics in completely siliceous zeolite ZSM-5 by FT-Raman spectroscopy.

In the present work, binary adsorption of p-xylene and toluene in completely siliceous zeolite ZSM-5 was examined by FT-Raman spectroscopy in combination with powder X-ray diffraction. The results indicate that at total loadings of < or = 4 molecules per unit cell (u.c.) both p-xylene and toluene molecules prefer to reside at the intersections of straight and zigzag channels. The structure of the sorbate/sorbent complexes likely belongs to orthorhombic. At high loadings of 7 and 8 molecules/u.c., the framework of the zeolite transforms to another orthorhombic phase. In this high-loaded phase, toluene molecules are distributed evenly in both the channel intersection and the midsection of straight channel. Although p-xylene has access to both the channel intersection and the zigzag channel, it does show a slight preference for the channel intersection. The adsorptive behavior of these aromatics at intermediate total loadings of 5 and 6 molecules/u.c. is more complicated because the zeolitic framework is a mixture of two different orthorhombic phases.

Journal Article↗

PubMed2006

CASCSF study on the photochemical transposition reactions of pyrazines.

Several reaction pathways for the photochemical transformations of methyl-substituted pyrazine in its first excited state 1(pi --> pi*) have been determined using the CASSCF (six-orbital/six-electron active space) and MP2-CAS methods with the 6-311G(d) basis set. Our model investigations suggest that conical intersections play a crucial role in the photoisomerization of pyrazines. Moreover, the present theoretical findings indicate that all of the photoisomerizations of pyrazines adopt the same reaction path as follows: pyrazine --> Franck-Condon region --> conical intersection --> pyrimidine. That is, although an excited-state pyrazine molecule can initiate a phototransposition process easily, this process can be completed on the ground-state potential energy surface after passage through a conical intersection where a fast, radiationless decay is possible. The existence of these nonadiabatic reaction pathways is consistent with the available experimental observations of the photochemistry and photophysics of pyrazine and its methyl derivatives. In the present work, we propose a simple p-pi orbital topology model, which can be used as a diagnostic tool to predict the location of the conical intersections, as well as the geometries of the phototransposition products of various heterocycles.

Journal Article↗

PubMed2006

Photochemical isomerization reactions of cyanopyrroles: a theoretical study.

The mechanisms of the photochemical isomerization reactions were investigated theoretically using a model system of 2-cyanopyrrole and 2-cyano-5-methylpyrrole with the CASSCF (eight-electron/seven-orbital active space) and MP2-CAS methods and the 6-311(d,p) basis set. The structures of the conical intersections, which play a decisive role in such phototranspositions, were obtained. The intermediates and transition structures of the ground state were also calculated to assist in providing a qualitative explanation of the reaction pathways. Our model investigations suggest that the preferred reaction route for the cyanopyrroles is as follows: reactant --> Franck-Condon region --> conical intersection --> photoproduct. In particular, the conical intersection mechanism found in this work gives a better explanation than the previously proposed internal cyclization-isomerization mechanism and supports the experimental observations. In addition, we suggest a simple p-pi orbital topology model, which can be used as a guide tool to predict the location at which conical intersections are likely to occur, as well as the conformations of the phototransposition products of various heterocycles.

Journal Article↗

PubMedDate not supplied

Intrachain reaction of a pair of reactive groups attached to polymer ends. II. Monte carlo study on the intrachain reaction proceeding on trans/cis-polysarcosine chain.

Monte Carlo calculation was performed to evaluate the ring-closure probability of short polysarcosine chains. Calculations were made for unperturbed trans- non-self-intersecting trans-, and non-self-intersecting trans- and non-self-intersecting trans/cis-polysarcosine chains. In the latter case, the main chain amide bond was allowed to take cis as well as trans conformations. The ring-closure probability for unperturbed trans-polysarcosine chains was found to be substantially greater than for non-self-intersecting trans chains. Virtually no difference was observed between the ring-closure probability was used to estimate the cyclization constant, i.e., the ratio of rate constant for the intramolecular reaction of the two groups attached to the polymer ends to that of the intermolecular one. The results were compared with the experimental data for the intrachain reaction proceeding on polysarcosine chain reported in the first paper of this series. The Monte Carlo results roughly reproduced the experimental data and the calculated chain length dependence was consistent with the observed one for longer chains.

Binding Sites↗

PubMed1997

Assigned versus participative goal setting and response generalization: managing injury control among professional pizza deliverers.

Safety belt use, turn signal use, and intersection stopping were observed at 3 pizza delivery locations per driver's license plate numbers. After baseline observations, employees at 1 store participated in goal setting targeting complete stops. Employees at the other store were assigned a goal. Over 4 weeks, the group's percentages of complete intersection stopping were posted. Both intervention groups significantly increased their complete intersection stops during the intervention phase. The participative goal-setting group also showed significant increases in turn signal and safety belt use (nontargeted behaviors) concurrent with their increases in intersection stopping (targeted behaviors). Drivers decreased their turn signal and safety belt use concurrent with the assigned goal condition targeting complete stops.

Accidents, Occupational↗

PubMed1995

Secondary homoclinic bifurcation theorems.

We develop criteria for detecting secondary intersections and tangencies of the stable and unstable manifolds of hyperbolic periodic orbits appearing in time-periodically perturbed one degree of freedom Hamiltonian systems. A function, called the "Secondary Melnikov Function" (SMF) is constructed, and it is proved that simple (resp. degenerate) zeros of this function correspond to transverse (resp. tangent) intersections of the manifolds. The theory identifies and predicts the rotary number of the intersection (the number of "humps" of the homoclinic orbit), the transition number of the homoclinic points (the number of periods between humps), the existence of tangencies, and the scaling of the intersection angles near tangent bifurcations perturbationally. The theory predicts the minimal transition number of the homoclinic points of a homoclinic tangle. This number determines the relevant time scale, the minimal stretching rate (which is related to the topological entropy) and the transport mechanism as described by the TAM, a transport theory for two-dimensional area-preserving chaotic maps. The implications of this theory on the study of dissipative systems have yet to be explored. (c) 1995 American Institute of Physics.

Journal Article↗

PubMed2006

Ab initio nonadiabatic quantum dynamics of cyclohexadiene/hexatriene ultrafast photoisomerization.

Reaction mechanisms of the ultrafast photoisomerization between cyclohexadiene and hexatriene have been elucidated by the quantum dynamics on the ab initio potential energy surfaces calculated by multireference configuration interaction method. In addition to the quantum wave-packet dynamics along the two-dimensional reaction coordinates, the semiclassical analyses have also been carried out to correctly estimate the nonadiabatic transition probabilities around conical intersections in the full-dimensional space. The reaction time durations of radiationless decays in the wave-packet dynamics are found to be generally consistent with the femtosecond time-resolution experimental observations. The nonadiabatic transition probabilities among the ground (S0), first (S1), and second (S2) excited states have been estimated by using the semiclassical Zhu-Nakamura formula considering the full-dimensional wave-packet density distributions in the vicinity of conical intersections under the harmonic normal mode approximation. The cyclohexadiene (CHD) ring-opening process proceeds descending on the S1(1 1B) potential after the photoexcitation. The major part of the wave-packet decays from S1(1 1B) to S1(2 1A) by the first seam line crossing along the C2-symmetry-breaking directions. The experimentally observed ultrafast S1-S0 decay can be explained by the dynamics through the S1-S0 conical intersection along the direction toward the five-membered ring. The CHD: hexatriene (HT) branching ratio is estimated to be approximately 5:5, which is in accordance with the experiment in solution. This branching ratio is found to be mainly governed by the location of the five-membered ring S1-S0 conical intersection along the ground state potential ridge between CHD and HT.

Journal Article↗

PubMed2000

Slope and the Zöllner illusion.

Informal observation suggests that the magnitude of the Zöllner illusion is reduced when the figure is viewed on a sloping plane. The hypothesis that this effect derives from the enlargement of the acute angle of intersection between the obliques and the verticals in the figure when it is viewed on a sloping plane is here investigated. The magnitude of the Zöllner illusion was measured with the use of a visual analogue scale. The results show that the change in the magnitude of the Zöllner effect as a function of the slope of the figure is different from that for corresponding figures, with enlarged angles of intersection between the obliques and the verticals, presented vertically. It is concluded that the enlargement of the angles of intersection can only partly account for the reduction of the Zöllner effect when the figure is viewed under slope, and that some other factor must be involved. An alternative hypothesis is evaluated whereby the effects result from the diminution in the contrast of the obliques when the figure is viewed under slope. Data are also presented to show that observers are able to perceive the enlarged or foreshortened angles of intersection veridically.

Adult↗

PubMed1983

Spatial knowledge of young and elderly adults: scene recognition from familiar and novel perspectives.

Thirty young adults (mean age = 25.3) and 30 elderly adults (mean age = 65.3) were tested on a memory task in which they were asked to recognize environmental scenes from familiar and novel perspectives. Participants initially viewed slides of 10 business and 10 residential street intersections. Pairs of intersections were then presented and subjects were asked to select the intersection viewed previously. During the recognition phase subjects saw the intersections from the original perspective (0 degrees), rotated 90 degrees from the original perspective, or rotated 180 degrees from the original perspective. Young adults were more accurate than elderly adults and accuracy was greater for business than residential scenes at both age levels. Subjects were more accurate in the 0 than 180 degree condition, while performance in the 90 degree condition was significantly less accurate than in the other two conditions. These results indicate that (1) young adults have better recognition memory than elderly adults for real world scenes, and (2) environmental differentiation aids recognition memory for spatial locations.

Adult↗

PubMedDate not supplied

Characteristics of fatal ambulance crashes in the United States: an 11-year retrospective analysis.

BACKGROUND: Ambulance crashes have become an increasing source of public concern. Emergency medical services directors have little data to develop ambulance operation and risk management policies. OBJECTIVE: To describe fatal ambulance crash characteristics, identifying those that differentiate emergency and nonemergency use crashes. METHODS: This was a retrospective analysis of all fatal ambulance crashes on U.S. public roadways reported to the Fatality Analysis Reporting System (FARS) database from 1987 to 1997. Main outcome measures were 42 variables describing crash demographics, crash configuration, vehicle description, crash severity, and ambulance operator and vehicle occupant attributes. RESULTS: Three hundred thirty-nine ambulance crashes caused 405 fatalities and 838 injuries. These crashes occurred more often between noon and 6 PM (39%), on improved (99%), straight (86%), dry roads (69%) during clear weather (77%), while going straight (80%), through an intersection (53%), and striking (81%) another vehicle (80%) at an angle (56%). Most crashes (202/339) and fatalities (233/405) occurred during emergency use. These crashes occurred significantly more often at intersections (p < 0.001), at an angle (p < 0.001), with another vehicle (p < 0.001). Most crashes resulted in one fatality, not in the ambulance. Thirty pedestrians and one bicyclist comprised 9% of all fatalities. In the ambulance, most serious and fatal injuries occurred in the rear (OR 2.7 vs front) and to improperly restrained occupants (OR 2.5 vs restrained). Sixteen percent of ambulance operators were cited; 41% had poor driving records. CONCLUSIONS: Most crashes and fatalities occurred during emergency use and at intersections. The greater burden of injury fell upon persons not in the ambulance. Rear compartment occupants were more likely to be injured than those in the front. Crash and injury reduction programs should address improved intersection control, screening to identify high-risk drivers, appropriate restraint use, and design modifications to the rear compartment of the ambulance.

Accidents, Occupational↗

PubMed2006

Analyses of rear-end crashes based on classification tree models.

OBJECTIVE: Signalized intersections are accident-prone areas especially for rear-end crashes due to the fact that the diversity of the braking behaviors of drivers increases during the signal change. The objective of this article is to improve knowledge of the relationship between rear-end crashes occurring at signalized intersections and a series of potential traffic risk factors classified by driver characteristics, environments, and vehicle types. METHODS: Based on the 2001 Florida crash database, the classification tree method and Quasi-induced exposure concept were used to perform the statistical analysis. Two binary classification tree models were developed in this study. One was used for the crash comparison between rear-end and non-rear-end to identify those specific trends of the rear-end crashes. The other was constructed for the comparison between striking vehicles/drivers (at-fault) and struck vehicles/drivers (not-at-fault) to find more complex crash pattern associated with the traffic attributes of driver, vehicle, and environment. RESULTS: The modeling results showed that the rear-end crashes are over-presented in the higher speed limits (45-55 mph); the rear-end crash propensity for daytime is apparently larger than nighttime; and the reduction of braking capacity due to wet and slippery road surface conditions would definitely contribute to rear-end crashes, especially at intersections with higher speed limits. The tree model segmented drivers into four homogeneous age groups: < 21 years, 21-31 years, 32-75 years, and > 75 years. The youngest driver group shows the largest crash propensity; in the 21-31 age group, the male drivers are over-involved in rear-end crashes under adverse weather conditions and the 32-75 years drivers driving large size vehicles have a larger crash propensity compared to those driving passenger vehicles. CONCLUSIONS: Combined with the quasi-induced exposure concept, the classification tree method is a proper statistical tool for traffic-safety analysis to investigate crash propensity. Compared to the logistic regression models, tree models have advantages for handling continuous independent variables and easily explaining the complex interaction effect with more than two independent variables. This research recommended that at signalized intersections with higher speed limits, reducing the speed limit to 40 mph efficiently contribute to a lower accident rate. Drivers involved in alcohol use may increase not only rear-end crash risk but also the driver injury severity. Education and enforcement countermeasures should focus on the driver group younger than 21 years. Further studies are suggested to compare crash risk distributions of the driver age for other main crash types to seek corresponding traffic countermeasures.

Acceleration↗

PubMed2005

Application of spatial modulation of magnetization (SPAMM) to children: the effect of image resolution on tagging pattern.

BACKGROUND AND OBJECTIVE: Spatial modulation of magnetization (SPAMM) is a valuable magnetic resonance imaging technique for studying ventricular biomechanics. In order to track the intersection points of the stripes to calculate regional wall motion and strain, the stripe spacing should be at most half the wall thickness, yet sufficiently larger than the image pixel size in order that the stripes be well resolved. These conflicting requirements, that the grid spacing be much smaller than the wall thickness yet much larger than the pixel size, are relatively easy to meet in adult subjects but are difficult in children because of their small size. The purpose of this study was to delineate the effect of pixel size relative to SPAMM grid spacing on the stripe pattern produced by SPAMM with application towards its use in children and to present a new approach to the analysis of these images. METHODS: We performed SPAMM imaging on a 1.5 Telsa Siemen's Vision MR system on a phantom, using an artificial ECG (R-R interval = 450 ms for triggering), holding the pixel size constant and varying the degree of stripe spacing. We used both square (1 mm) and rectangular (1 mm by 2 mm) pixels. We express the ratio of grid to pixel size as the ratio of the center-center spacing of the grid lines to the horizontal pixel size. We retrospectively reviewed the SPAMM images on 10 patients with a ratio of grid to pixel size approximately 4:1 and 10 with a ratio of grid to pixel size approximately 8:1. We further performed SPAMM imaging in four patients with different grid to pixel size ratios in the same patient. Finally, we tested a new algorithm to track the signal intense regions rather than the signal poor intersection points of the grid lines, which were compared on three ventricles with SPAMM tagging. RESULTS: In a phantom, the effect of decreasing the separation between stripes while keeping the resolution of the image constant changed the stripe pattern from a series of two parallel lines perpendicular to each other to a "checkerboard" pattern. With a relative grid:pixel ratio of 8:1 as used with adult studies, the dark bands and the crossing points are well defined. As the ratio decreases from 8:1 to 6:1, the black band is less well resolved. When the resolution is reduced further to a grid:pixel ratio of 4:1, the image appears to be a checkerboard of white and dark squares. This occurred with both square and rectangular pixels. The effect in vivo is similar. When the ratio is approximately 8:1, all patients demonstrated a stripe pattern as a set of parallel lines perpendicular to each other. When the ratio was approximately 4:1, all patients demonstrated the stripe pattern as checkerboard. This was found to be the case in the same patient, whether varying the pixel size by changing the field of view or matrix or by changing the grid spacing. We also found that tracking the signal intense regions was equivalent to tracking the signal poor intersection points of the grid, and this approach was much easier to implement. CONCLUSION: With decreasing ratio of grid spacing to pixel size, SPAMM stripe patterns change from a set of parallel lines perpendicular to each other to a "checkerboard" pattern. This effect has implications for tracking techniques to determine strain and wall motion. At smaller ratios, as is needed sometimes in children, it is easier to track the signal intense regions rather than the "intersection" points of the stripes. Both these approaches to tracking are equivalent.

Adolescent↗

PubMed1993

A new composite model of objects for Monte Carlo simulation of radiological imaging.

A composite object model is proposed for Monte Carlo simulation of radiological imaging systems. The composite model contains four components: a set of regular and 'voxelized' primitives, a 'modular' inclusion tree, a set of designated constructive solid geometry (CSG) trees, and a mapping from the set of CSG trees to the inclusion tree. The voxelized primitive is a primitive containing a stack of voxels whose intersections with a photon path are calculated based on Siddon's method. The inclusion tree is employed to describe the inclusion relationships of homogeneous subregions of material characteristics in larger regions in an object. The model is designed so that the 'divide-and-conquer' principle for modular software design can be used to construct an inclusion tree for a complex object. The designated CSG trees are used to model source distributions. The mapping from the inclusion tree to the CSG trees provides the fundamental information for the initial location of a photon history in the tree. Computational issues are addressed for the new model. For the modular inclusion tree, a computationally efficient algorithm is proposed in conjunction with the determination of the photon-ray intersections with primitive and voxel boundaries as well as with the identification of the material characteristics for each ray segment between two adjacent intersections. For source distributions, the designated CSG trees are defined based on the set intersections-difference-unions (IDU) operation sequence. The IDU operations present computation advantages over existing source modelling based on a single inclusion tree. For voxelized primitives, a new sampling technique called the fractional photon emission technique is introduced to reduce sampling computations for existing techniques based on single photon emission. The composite model is an extension of existing simple-geometry, solid-geometry, and voxel-based models and hence provides greater flexibility for model optimization. Based on the composite model, two objects were simulated: an anthropomorphic thorax with lesion inserts for transmission studies and a 3D Hoffman brain phantom with lesion inserts for emission studies. The simulations demonstrate the flexibility of the composite approach in modelling objects for clinically significant applications.

Computer Simulation↗

PubMed2002

Effectiveness of virtual reality for teaching pedestrian safety.

Sixty percent to 70% of pedestrian injuries in children under the age of 10 years are the result of the child either improperly crossing intersections or dashing out in the street between intersections. The purpose of this injury prevention research study was to evaluate a desktop virtual reality (VR) program that was designed to educate and train children to safely cross intersections. Specifically, the objectives were to determine whether children can learn pedestrian safety skills while working in a virtual environment and whether pedestrian safety learning in VR transfers to real world behavior. Following focus groups with a number of key experts, a virtual city with eight interactive intersections was developed. Ninety-five children participated in a community trial from two schools (urban and suburban). Approximately half were assigned to a control group who received an unrelated VR program, and half received the pedestrian safety VR intervention. Children were identified by group and grade by colored tags on their backpacks, and actual street crossing behavior of all children was observed 1 week before and 1 week after the interventions. There was a significant change in performance after three trials with the VR intervention. Children learned safe street crossing within the virtual environment. Learning, identified as improved street-crossing behavior, transferred to real world behavior in the suburban school children but not in the urban school. The results are discussed in relation to possibilities for future VR interventions for injury prevention.

Accidents, Traffic↗