Kerbstone
/ˈkɜːrbstəʊn/
Definition 1 of 1
Pro Tip 1/3Roadside Indicator
Kerbstones are helpful indicators of where the pavement meets the road, guiding pedestrians. 
He glanced down to check the kerbstone before stepping off the pavement.
Pro Tip 2/3Parking Guide
Kerbstones also guide drivers when parking; too far from the kerbstone may obstruct traffic. 
Ensure your car's wheels are close to the kerbstone when parallel parking.
Pro Tip 3/3British Spelling
Remember 'kerbstone' is a British English term; American English uses 'curbstone'. 
He tripped over a loose kerbstone on the London street.