Rollover protection and wheelchair securement for special transportation systems
Report no. Mn/DOT 1997-11
This report examines the Minnesota Rules that pertain to rollover protection and wheelchair securement in vehicles that provide Special Transportation Services (STS) for elderly and disabled populations. Large vans converted for STS needs have a raised roof that affords little rollover protection. Minnesota adopted the roof crush provision of FMVSS 220, and van converters responded by producing rollbar systems, passing costs on to transit providers. This assessment included a literature review, visits to van converters, and analytical estimates of center of gravity changes and aerodynamic efforts.
The report recommends that vans with raised roofs should comply with FMVSS 220 while those without raised roofs should comply with FMVSS 216 or 220. For wheelchair securement, a Minnesota Rule provides some detailed requirements for attaching securement devices to the vehicle. In some cases, the requirements differ from the manufacturer's instructions, which may compromise the strength. After review and discussion with installers, the report recommends following manufacturer's instructions and encouraging manufacturers to upgrade the quality of instructions.