Old surveyor here. Been at least a decade since i have been on site but in most cases, coloured flags denote underground services. Yellow is often for gas pipes, blue for water pipes and red for electricity cables. They can often be marked using road marking spray paint, with a line drawn to show the direction the services are running in. The info in the flags maybe how deep they are and who they belong to etc..
Old surveyor here. Been at least a decade since i have been on site but in most cases, coloured flags denote underground services. Yellow is often for gas pipes, blue for water pipes and red for electricity cables. They can often be marked using road marking spray paint, with a line drawn to show the direction the services are running in. The info in the flags maybe how deep they are and who they belong to etc..
Flags are used in the USA, when in Florida you see them everywhere on the grass verges when roadworks are being undertaken
Hopefully nothing that will stop the project
I doubt it.