What is the main operational advantage of placing HMA in a windrow and picking it up into the paver, compared with dumping every truck directly into the hopper?

1. It eliminates the need for any rollers
2. It can provide a more continuous head of remixed material and reduce stop-and-go paving at truck exchanges
3. It allows the mix to cool to ambient temperature before it enters the screed
4. It replaces tack coat because the windrow bonds itself to the old pavement