Readiness check

Is your milling and grade-control crew ready to cut?

A milling job either fixes the road's grade or copies its problems an inch lower, and that outcome is decided before the drum drops. Cut to an accurate depth and a true grade reference, run good teeth, protect the castings and the drop-off, and hand off a clean surface, and the overlay rides right. Skip any one of those and the overlay inherits the failure you were paid to remove, or the job turns into a claim over a sharp edge or a hit casting.

1. Have you confirmed the mill depth and the cross-slope against the project and DOT specification before the drum drops?Both the depth and the cross-slope are read off the contract and DOT spec, written down, and confirmed with the crew before the first pass.We know the depth number but are holding cross-slope off habit or the old surface, or we haven't checked the spec value.We set what the last job used and check the paperwork later if there's a question.

2. Is the grade and cross-slope reference set to something other than the old pavement, to the tolerance the spec requires?The drum runs off a chosen reference (stringline, averaging beam, sonic sensor, or a 3D model) set to the spec tolerance, and for 3D the model and localization are checked against known control.We run a short ski or a single sensor off the adjacent surface and trust it's close enough for this cut.The machine runs off its own tracks on the existing surface, so it copies the old profile back an inch lower.

3. Have you located and marked every manhole, valve, monument, and grate in the cut, on the surface and on a plan?Every casting is found, marked on the ground and on a plan, and lowered or flagged before the machine reaches it.The obvious ones are marked, but we're relying on the operator to catch the rest from the cab.We find them as we go and lift the drum when we see one.

4. Have you walked the drum for teeth condition, tooth rotation, and water spray before cutting?Walked at shift start and through the day: full set of sharp teeth, all free to rotate, frozen holders freed, water spray flowing.We eyeball the drum at the start but don't recheck through the shift or watch the water nozzles.We run until the surface streaks or ridges, then look at the teeth.

5. Do you measure the cut depth on the first pass across the full width, then recheck it through the shift?Tape or depth gauge at several points across the width on the first pass, rechecked whenever the surface or the machine changes.We check depth once at one spot and trust the cab readout after that.We go by the machine setting and let the cores sort it out later.

6. Do you check the milled cross-slope and grade behind the machine with a smart level and rod, not just the readout?Smart level across the lane and a rod off the benchmark behind the machine, hunting the systematic error, with the readings logged.We glance at the slope readout and put a level on it now and then.We trust the machine's display and don't put anything on the finished surface.

7. Is the milled drop-off managed for live traffic with ramps, signs, and the time limits from the traffic-control plan and AHJ?The drop-off, the transitions, and any lowered castings are treated with wedges, signs, and edge marking per the TCP and AHJ, within the time limit.We sign the work but leave the vertical edge open overnight without a wedge or ramp.The open edge stays exposed to traffic with no treatment until the overlay goes down.

8. Is the surface swept and the fine dust knocked down before tack and overlay?Swept, then a power broom or flush knocks down the fine dust, and the texture is checked clean and open before tack.One pass with a mechanical broom and then straight to tack.We tack over the loose millings and dust to keep the job moving.