These panels of asbestos cement were flytipped in Brandy Hole Lane on Saturday with another load found dumped in West Ashling on Sunday.
The scattered debris of roof panels covered the carriageway in Brandy Hole Lane, making it dangerous to travel through in the dark.
A second pile of waste materials was discovered the following day in Ratham Lane.
Chichester District Council said highways were aware and roads were being cleared.
To report flytipping, visit the district council website at https://www.chichester.gov.uk/article/27780/Report-a-problem