Remove roads and bridges from raster

Hi everyone,

After I created the raster data from Flow accumulation, the stream lines are disconnected from the real. I mean when I compared the stream lines from flow accumulation and the flow path on Google Earth, they are totally different due to roads and bridges obstructing the flow. I heard someone said that you have to create dam-break shapefiles > feature to raster > reclassify > condition. However,those steps don't work well ... is there any way to remove the roads or the bridge from rater data that I can run properly flow accumulation without obstruction from roads and bridges?

I highly appreciate your help and assistance.

Pych