Waterloo Road Car Park

My 83 year old mum tripped over the speed bump style small hump going into the carpark in the twilight at 5pm one night last week. She is sprightly and mobile but this seemingly ill placed hump had her sprawling onto hard tarmac- damaged hands and knees- luckily not her face. Why is it lined white- shouldn't it be yellow? Or better still orange ir have some warning signs?
BEWARE- this is not safe