What if Engineers could build bridges in a similar way to them building walls? They count towards the same resource, and look similar. Bridge blocks can only be built on water brushes, to prevent engies from blocking off other things with them. These bridges are the same strength as walls, but allow for vehicle passage over water. This will actually make engineers do what they do in real life armies: change terrain. If this is a working suggestion, it could be possible to replace the emp_slaughtered bridge with this.