Traffic Jams on the course

Almost every golfer I know is concerned about slow play.  There are many reasons for it.  A lot of the blame goes to golfers who simply aren't ready to hit when it is there turn, but not all of it.  Anyone who regularly drives on a crowded freeway frequently experiences traffic jams.  Everyone on the road is moving as fast as they can and keeping on the bumper of the car in front, but doing so doesn't really help anyone move faster, and the time to drive 10 miles can go from 10 minutes to an hour very easily without anyone on the road being to blame.  What people rarely realize is that this same kind of traffic jam can happen on a golf course, stretching the time for a round from 3-1/2 or 4 hours up to 5 or even 6 hours.  

What causes backups

Traffic backups basically occur whenever you have more people arriving somewhere than leaving.  It could be cars on a freeway, people waiting to use an ATM, water flowing into a sink with a slow drain, or even golfers on a golf course.  On a typical weekday afternoon in a city, more cars are entering the outbound freeways than are passing the city limits as they leave.  When this happens, the "extra" cars simply back up on the freeway, lengthening the time it takes each car entering the freeway to get through.  Exactly the same thing happens on the golf course whenever the spacing of tee times is such that golfers are being put on the course faster than they can play through some point on the course.

What determines capacity?

On a freeway, a key factor in traffic jams is the capacity of the road to carry traffic.  This is in essence the number of cars per hour that can move through a point on the road.  If cars enter the freeway faster than this, it backs up.  For a freeway it's determined by the number of lanes, the spacing between cars, and the speed of the road.  For a golf course, the equivalent is how many groups can play through a particular hole in an hour, which is determined by the time between when the group in front clears a particular spot (the green or maybe the fairway off the tee), and when your group manages to clear the same spot for the group behind.  The slowest such time on the course for any spot on the course will determine how many groups per hour the course can handle without backups.

To see this, let's say the slowest spot on the course to play past -- usually the green of a long par 3, takes 12 minutes on average for a group to play past.  By this I mean that once the group ahead finishes the hole it takes your group 12 minutes to hit 4 tee shots, play to the green, putt out, and move out of the way so the next group can hit.  This means that 5 groups per hour will move past this hole.  If the tee times are spaced 12 minutes apart,  5 groups per hour will enter the course, and will be able to move past the "bottleneck" hole, and nobody spends a lot of time waiting.  Ever seen a course with 12 minute tee time spacings?  I haven't, which is a major reason why traffic jams occur.  If the course has 10 minute spacing, 6 groups will be put on the course every hour, but only 5 will get past the bottleneck.  The extra group simply contributes to a lengthening backup.

The slowest hole to play through  isn't always at a par 3.  It could occur at a long par 4 or a reachable par 5.  The resulting backup doesn't always occur right behind it.  If the slow hole is a par 4 or 5, it is likely that the backup will occur at the tee, because groups are waiting to tee off for a group waiting in the fairway for those ahead to play the rest of the hole, putt out, and move away.

Backups and playing time.

The backup translates directly into longer playing times.   If nobody was waiting at the bottleneck at the beginning of the day, after an hour there would be one group waiting, 2 groups after 2 hours, 3 after 3 hours, etc.  Each extra group waiting lengthens the time it takes everyone behind them to play a round.  If the first group of the day plays in 4 hours, starting an hour later will take 4:12, 2 hours later 4:24, etc.  No wonder early morning tee times are popular!   On a real course, things won't always be this bad.  Specifically if a tee time is not filled, it removes one waiting group.  If some times are taken by twosomes or threesomes who play through the slow point faster, it will reduce the tendancy to back up.  On a fully booked Saturday AM, though, it's a virtual certainty that those teeing off at 11 will take an hour longer to finish than the first group off at 6.

The Shotgun death march.

Ever played in an event with a shotgun start that took forever to finish?  Most of us have, and it takes forever to finish even if you are playing in a "fast" format.  The bottleneck theory here will tell you why.  Most courses consider a "full" field for a shotgun even to be 144 players, 2 foursomes on each hole, or 36 groups total.  Now as those people go around the course, all 36 groups must get past whatever bottleneck is the slowest to play through.  Let's say that's 10 minutes, not a bad time at all for 4 people to play a long par 3.  Guess what, 36 groups at 10 minutes each is 6 hours to get through that point.  Excruciating.  In fact, for a full shotgun field to finish in 4 hours, the slowest hole must play no slower than 240 minutes/36 groups, or 6 minutes and 40 seconds.  That's completely unrealistic, which is why most big shotguns are on the course closer to 6 hours or more than 4.  The good news here is that there's a simple solution -- just don't put as many groups on the course!  Reduce the number to 24 groups and 10 minutes is fast enough.

How do you eliminate backups?

The backup is created whenever more groups enter the course than can play through the bottleneck.  To solve the problem we have to change either the rate at which new groups start, or the rate at which they move through the bottleneck hole.

Limiting input

Some cities try to limit jams on their freeways by placing traffic lights on the entrance ramps and limiting how many cars can enter the freeway during rush hour.  It works up to a point, though if more commuters want to leave the city it may just shift the backup from the freeway to the city streets approaching the freeway.  Tee times serve the same purpose on a golf course.  By spacing out the groups starting, even if the first hole can be played quickly, the course operator insures that people can play through the whole  course without backups.  If they don't do this and let people tee off as soon as the group ahead is out of the way, the extra groups allowed onto the course will contribute to a backup later on.  This is very apparent on one course I play (St Andrews course 2 in West Chicago).  Tee times are spaced 7 minutes apart -- way too close, and the first hole is a very easy not quite reachable par 4, while the second hole is a very difficult and slow to play par 3.  It's not uncommon to find 5 groups waiting on the second tee, and probably no accident that the "half way house" is right next to that tee.

Course operators need to recognize this function of tee times, and avoid the temptation to squeeze a few more groups on, realizing that the extra greens fees won't be worth the lost business they get when everyone spends a lot of time waiting as a result.

Speeding up play through the bottleneck

Spacing tee times at 12 minute intervals may result in faster play, but fewer golfers will get to play if that's the case and few course operators will do it.  The only other alternative is figure out how to get more golfers through the bottleneck.  One factor is simply how fast the groups play the hole.  There are many ways to help speed up the slow hole:

How about waving the next group up?

There's a lot of debate over the wisdom of having each group allow the group behind to hit up before they finish.  The common strategy here is for each group to wave the group behind up when all of them have reached the green.  Does this help?  The answer isn't simple, and the best summary may be usually and marginally.  To understand this you have to understand how long it takes for each group to play each step of the hole.  Let's say the bottleneck hole takes 12 minutes to play that breaks down as follows:  2 minutes to tee off, 4 minutes to move from tee to the area of the green, 2 minutes to pitch any shots that missed onto the green, and 4 minutes to putt out and move away.  Now a naive view would be that allowing the next group to hit can't work, since It looks like this will add 2 minutes (the time spent waiting for the group behind to hit) to the time.  

Unfortunately it's not that simple, since it also enables the group behind to start on their time playing a little faster.  To understand what's happening, you have to look at the time interval between when one group finishes and the next group finishes.  Without hitting up, that was 12 minutes.  With hitting up, by the time one group finishes the group behind has already teed off and spent 4 minutes walking up to the hole, so what remains is 2 minutes hitting onto the green, 2 minutes waiting for the group behind, and 4 minutes putting out, or 8 minutes total.  So, in this case yes, hitting up will help a lot, reducing the time to play the bottleneck by 4 minutes!

Of course this is probably a very optimistic example.  Many factors influence how good hitting up will be:
Hitting up is, though, almost always going to result in faster play through the bottleneck. 

A variant of this strategy which I've almost never seen suggested is to have two groups hit to the hole at once, then play out in order.  This is less disruptive than waving the next group up, since nobody has to walk off the green and watch for incoming shots. Again, this works by overlapping the time it takes everyone to saddle up and get to the green, as well as some of the time the second group takes to prepare for their next shot (i.e. the members of the second group find their balls, select their clubs and prepare to hit while the first group is playing out. 

Parallel holes -- a radical solution.

One solution I've rarely seen is to remove the bottleneck by building two holes groups alternate in playing.  Say the bottleneck is number 3.  The course has "number 3" holes, 3A and 3B, and group 1 plays 3A, group 2 plays 3B, group 3 playce 3A, etc.  This is like adding a lane to a freeway and essentially doubles the capacity through the bottleneck, making it unlikely backups will occur there.  While this is an excellent solution technically, it's not likely to be a popular one, both because the land required for parallel holes is expensive and the experience for the players can be problematic  -- what if a group of players wants to hold a competition on that hole and they don't all play the same one?  Still, it's been tried  (Some of the Cog Hill courses have parallel par 3's to avoid backups).   Mostly though this is not the kind of thing a course designer usually thinks about when laying out a new course.  (Cog Hill was built by a man

Warren Montgomery