PREFERENCE FOR MAP SCALE OF IN-CAR ROUTE GUIDANCE AND NAVIGATION SYSTEM

Usability issues of maps presented in-car Route Guidance and Navigation System (RGNS) may result in serious impacts on traffic safety. To obtain effective RGNS, evaluation of ‘user satisfaction’ with the system has played a prominent role, since designers can quantify drivers’ acceptance about presented information. An important variable related to design of RGNS interfaces refers to select appropriate scale for maps, since it interferes on legibility of maps. Map with good legibility may support drivers comprehend information easily and take decisions during driving task quickly. This paper evaluates drivers’ preference for scales used in maps of RGNS. A total of 52 subjects participated of an experiment performed in a parked car. Maps were designed at four different scales 1:1,000, 1:3,000, 1:6,000 and 1:10,000 for a route composed of 13 junctions. Map design was based on cartographic communication principles, such as perceptive grouping and figure-ground segregation. Based on studies cases, we conclude intermediate scales (1:6,000 and 1:3,000) were more acceptable among drivers compared to large scales (1:1,000) and small (1:10,000). RGNS should select scales for maps which supports drivers to quickly identify direction of the maneuver and, simultaneously, get information about surroundings of route. More results are presented and implications discusse

EVALUATION OF USABILITY OF MAPS OF DIFFERENT SCALES PRESENTED IN AN IN-CAR ROUTE GUIDANCE AND NAVIGATION SYSTEM

Noise from the information communication process produced by the interfaces of navigation systems has overloaded drivers' cognitive processing systems and increased the probability of traffic accidents. This work evaluates the usability of maps of different scales in a prototype route guidance and navigation system. The maps were designed on basic cartographic communication principles, such as perceptive grouping and figure-ground segregation, as well drivers’ requirements for performing a tactical task. Two different scales were adopted, 1:3,000 and 1:6,000, and the maps implemented in the prototype. A total of 52 subjects (26 males and 26 females) participated in an experiment performed in a driving simulator. The maps describe an urban route composed of 13 simple and complex maneuvers. The drivers’ mental workload was measured in terms of visual demand, navigational error and subjective preference. Results reveal that the usability of maps is influenced by map scale variation, and this is related to maneuver complexity. Also, an association between drivers’ visual demand and gender was found, and this was related to drivers’ spatial ability. More implications are presented and discussed

INFLUÊNCIA DO GÊNERO NA DEMANDA VISUAL POR MAPAS EM ESCALAS DIFERENTES EM SISTEMA DE NAVEGAÇÃO E GUIA DE ROTA

Este trabalho investiga a influência do gênero do motorista na demanda visual por mapas dinâmicos exibidos em diferentes escalas em Sistemas de Navegação e Guia de Rota em Automóvel- SINGRA. Um grupo de 26 homens e 26 mulheres participou de um teste realizado em um simulador de direção de baixo custo. A tarefa do motorista consistiu em realizar uma viagem por uma rota desconhecida, auxiliado por um protótipo de SINGRA que exibe mapas em duas diferentes escalas. Este trabalho replica os achados da literatura a respeito de que há uma relação significativa entre o gênero e o desempenho em tarefas visuo-espacial. Os resultados mostram que motoristas de diferentes gêneros apresentam diferentes níveis de demanda visual, tanto para a variação da escala do mapa quanto para a variação da complexidade da manobra. Estes resultados são discutidos com base nas diferenças individuais em termos de habilidade espacial e ansiedade espacial

An ethnomethodological exploration of police officers’ use of a cognitive aid when encountering people with a potential mental disorder

Aim This study investigated a police officer’s situation awareness , when encountering a potentially mentally disordered person. This underpinned the development of a cognitive aid to support them during such encounters. Background Up to 40% of police encounters are associated with someone experiencing a mental disorder. Operational difficulties due to situational complexity, and the police officer’s ignorance regarding the features of mental disorder, often translate into flawed situation awareness. This study built upon the work of Wright et al. (2008) with Lancashire Constabulary. Method An ethnomethodological design was employed, viewed through the theoretical lenses of symbolic interactionism and Endsley’s (1988) situation awareness framework. Completed in two stages, stage one utilised narrative synthesis, and individual semi-structured interviews with eight police officers. Data was thematically analysed to identify emerging themes which underpinned the cognitive aid’s development. Stage two employed a pre-post-test design, utilising video vignettes, note-taking exercises, and focus group interviews with seventeen police officers. The cognitive aid was used operationally prior to conducting semi-structured interviews with ten police officers. Results Emergent themes identified that pre-encounter factors shaped police officers’ situation awareness. This governed their assessment of danger, often resulting in pre-set behaviours to control a situation. Police officers demonstrated improved situation awareness, recognising and responding to a greater range of features of mental disorder when they used the cognitive aid. Contribution of new knowledge This was the first study to explore a police officer’s situation awareness, when encountering a potentially mentally disordered person. It identifies features police officers associate with mental disorder. The findings highlighted the effect of pre-encounter factors and their influence upon the perception of danger. Significantly, the cognitive aid caused a paradigm shift from one defined by an assumption of criminality, to one defined by the interpersonal in which police officers recognised and responded to a person’s mental health and well-being