LATCH (Lower Anchors and Tethers for CHildren) usability in school buses and passenger vehicles

The present study was designed to assess LATCH (Lower Anchors and Tethers for CHildren) usability in both cars and school buses. Despite being designed to make child restraint system (CRS) installation in vehicles easier and with fewer opportunities for misuse, there have been reports that LATCH is not as easy to use, or as effective, as hoped. To date, there have been few systematic or experimental studies evaluating LATCH usability. Further, based on research demonstrating that small children in school buses are not protected from injury in the same manner as larger children, motor vehicle safety regulations now require LATCH anchorages to be installed on a proportion of seats in all school buses, allowing for the installation of CRS. The main objectives of the study were to assess LATCH usability in cars and school buses and to make recommendations to improve its design and labeling.

Forty-eight paid participants (younger vs. older; experienced vs. not experienced) installed CRS in a car and a school bus using three different types of lower anchorage connectors and top tethers. Dependent measures included time to install and remove the CRS, frequency and seriousness of errors, and subjective usability reports.

Surprisingly, many participants were not familiar with the LATCH system and believed that CRS should only be installed using the seat belt. Over 40% of participants did not know where the lower anchorage connectors were located in the car. While installation performance using LATCH was generally satisfactory (all CRS were installed correctly between 70 and 92% of the time), LATCH design improvements in terms of the CRS and both vehicles were identified.

The study results generated a number of recommended design improvements that would improve LATCH usability in cars and school buses. These include: 1) clearly identifying LATCH anchors in both vehicle types by using clear, conspicuous labels or pictograms; 2) making LATCH anchors in all vehicles more accessible; 3) designing LATCH components for CRS that are easy to use correctly, provide adequate feedback to users, and are difficult to misuse; 4) anticipating, and designing to minimize, incompatibility between CRS and vehicles; 5) using maximum seat spacing in school buses for seats equipped with LATCH anchors; and, most importantly, 6) raising awareness of LATCH in the driving public.