title: Usability issues concerning child restraint system harness design.
abstract: A study was conducted to assess usability issues relating to child restraint system (CRS) harness design. Four convertible child restraint systems representing a wide variety of design features were used. Forty-two participants installed two child test dummies in both forward- and rear-facing configurations either inside or outside a test vehicle. Observer-scored checklists determined the degree to which each harness was installed correctly. Participant-scored questionnaires evaluated the 'ease-of-use' of various design features. While the percentage of correct installations exceeded 83% for all designs when installed in the forward-facing configuration, in the rear-facing position (that intended for children under 9-10 kg), there was a significant (between 65 and 89%) percentage of incorrect installations for all models. This finding is of particular interest and may be indicative of a more generalized problem with 'convertible' CRS designs when they are used in the rear-facing configuration. Furthermore, while certain design features were perceived by users as providing significantly better protection in the event of a collision, these also tended to be the features that were misused most often. The benefits and costs of various design features are discussed, and a method to test harness design usability is presented.
authors.affiliation: Ergonomics Division, Road Safety and Motor Vehicle Regulation Directorate, Transport Canada, 330 Sparks Street, 8th Floor, Ottawa, Ont., Canada K1A 0N5. brownc@tc.gc.ca
authors.forename: Christina M
authors.initials: CM
authors.lastname: Rudin-Brown
authors.forename: Jason K
authors.initials: JK
authors.lastname: Kumagai
authors.forename: Harry A
authors.initials: HA
authors.lastname: Angel
authors.forename: Kim M
authors.initials: KM
authors.lastname: Iwasa-Madge
authors.forename: Y Ian
authors.initials: YI
authors.lastname: Noy
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001336:Automobiles; D002648:Child; D002675:Child, Preschool; D016000:Cluster Analysis; D004867:Equipment Design; D005260:Female; D006801:Humans; D007223:Infant; D015370:Infant Equipment / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D012149:Restraint, Physical / Q000706:statistics & numerical data*; D012449:Safety / Q000706:statistics & numerical data; D012622:Seat Belts / Q000706:statistics & numerical data*; D013597:Systems Analysis