When there are a lot of construction sites that are inaccessible to normal trucks and need to be handled by amphibious trucks instead, it causes normal trucks to try to path to those sites for long periods of time in between jobs they can do. This causes other jobs to be neglected and pile up. For example the slag on my island is not getting moved properly even though there should be enough trucks to handle it because they are instead all just standing there trying to do construction jobs they can't reach instead.
I discovered this issue after placing down a very long bridge with a lot of segments that goes across the ocean to another area on my island. I think this is also causing amphibious trucks to haul materials somewhat erratically, preferring to go to distant bridge segments and not carry materials to multiple segments(eg. when a segment needs just 3 more steel but neighboring segments still need lots more, usually you'd expect a truck to carry a full load and the excess to 'overflow' to those neighboring segments, but instead they just carry the 3 steel and no more). As a result the throughput of my normal trucks has plummeted.
