The cleaning is largely a solved problem too.. You don't need 50 $10k/year people with squeegees, you just need one person in a $50k truck. https://www.alibaba

The cleaning is largely a solved problem too.. You don't need 50 $10k/year people with squeegees, you just need one person in a $50k truck. https://www.alibaba.com/product-detail/China-Road-tunnel-wall-cleaning-vehicle_60770674771.html?spm=a2700.7724857.normalList.5.63a52b09SAEP3y https://www.alibaba.com/product-detail/China-Road-tunnel-wal...