in‧road [usually plural]
to have an important effect or influence on something, especially by taking something away from it:
Video is making huge inroads into attendance figures at movie theaters (=taking away its customers).
They have made significant inroads into the European market.
The administrative workload is making massive inroads into our working day (=taking away time).
to make some progress towards achieving something difficult:
We haven't made much of an inroad into the backlog of work.