The summer months bring warm weather, vacations, more time spent outside and…road construction.  Because of the cold and snow during the winter months in the northeast, road construction and repair stops during that period.  As a result, it all must be done during the summer.  So I was prepared a few days ago when I entered NYS route 390 and saw a road repair crew on the north bound side of the road.  I thought that it was fortunate that they were not on my side, the south bound side, because I didn't have to slow down on the way to my appointment. 

Later that day, on my way home, I noticed that what was being done was a repair of the shoulder.  In the Rochester area, Route 390 is a six lane highway.  North of Interstate 490, which it intersects, it is a state road; south of 490 it is an Interstate.  So the crews doing the repair that I am referring to were part of the NYS Transportation Department.  Each direction of the road has three concrete lanes with asphalt shoulders.  Approximately 3.5 miles of these asphalt shoulders were badly cracked and in need of repair.  As I sped northbound on my way home from my appointment I had to slow down for the construction and so I was given the opportunity to have a better look at what was happening.  I didn't think much of it until the next day when I went south again and had to slow down because the crew had switched to the south bound lanes.  It occurred to me that they did not spend much time on the north bound shoulders and so I took a closer look at what hey were doing.

The lead machine was an asphalt scraper which dug up the cracked asphalt shoulder.  The broken pieces are thrown onto a conveyor which dumps them into a dump truck which is following closely behind it.  When the dump truck gets full, another is waiting to take its place. The asphalt scraper never stops and the shoulder is continuously removed.  What remains is a solid base which will readily accept new asphalt.  Several hundred yards behind this removal operation was a vehicle with a large brush mounted on the front.  It swept the shoulder area free of loose particles.  Several hundred yards behind the brushing operation was a crew which was laying fresh asphalt.  The asphalt was delivered in a large trailer and applied in a fairly even layer on the shoulder.  When this trailer became empty, another full trailer was waiting to take its place.  Here again, the addition of the new asphalt never stopped.  Several hundred yards behind the application operation was a roller which smoothed and finished the shoulder.  There was nothing behind the roller because now the job was done.  What I had witnessed was Lean Thinking applied to highway repair.

As I thought about this, I thought of the advantages that this method had over the previous methods that I had seen.  Usually, each step would be done independently.  One day the old asphalt would be removed.  Some days later it would be repaved.  Naturally, every time work is done on a road, safety cones must be put down and then picked up.  Traffic is disrupted. With the 'lean' method, it appeared that the cycle time for the job would be reduced.  That was good news for me, the consumer, because it was less of an imposition on my driving.  In addition, I thought that it might be possible to use fewer people because some could float between operations.  The total cost would be reduced because of fewer man hours.  Weather might also be a factor affecting scheduling.  If it rains heavily, for example, work has to stop.  With a lean operation, everybody would stop and start again as a team.  With separate operations, if the first operation got delayed, the later operations would have to reschedule all of their other work.  I thought that this is why I would usually see asphalt being removed one day and repaving taking place what seemed like weeks later.  Safety is also an issue on road work.  The less time people have to spend on an active roadway, the better off everyone is from a safety standpoint.

I spoke with Wayne Blattner, the General Foreman of the NYS Highway maintenance for this area and asked him about this operation.  He said that he had heard about Lean Manufacturing, but he had not attended any conferences on it specifically.  He has attended conferences on work reduction methods.  He said that he is down to "minimum" crews and thought that by combining operations he would make better use of the operators. As I thought, fewer total operator hours are required when operations are combined.  He stated that this project would take about 7 1/2 days and included fourteen miles of shoulder repair (four sections of 3 1/2 miles each).  Although he could not give  me an estimate of the cycle time with separate operations, I would think that it would be about two times this  or fifteen days.  Thus direct value to the customer is less disruption of traffic.  Indirect value is lower cost of road repair due to few man  hours required.  Benefit to suppliers would be the chance of more consistent scheduling.

We are used to seeing Lean Thinking on the manufacturing floor and have seen it in engineering and the medical field.  Now, thanks to Wayne Blattner, we can see it on our highways.