The Fife ITS basically extends the existing network of overhead gantries with variable message signs further north, allowing lanes on the M90 from Halbeath southwards to have variable speed limits applied, lanes marked off and so on.

Secondly the hard shoulder southwards from Halbeath is also being modified to allow it to be used as a bus lane at peak periods, and revert to a normal hard shoulder at other times.

Finally traffic lights will be installed on southbound slip roads from Halbeath southwards. These will allow what is called “ramp metering” – restriction of the flow of traffic on the “on ramps” in order to smooth the flow of vehicles.

As far as the extent of the 40mph zone goes, I suspect the extra length at each end is an attempt to stabilise as much as possible the traffic flow through the area at peak times – which is when things get tricky. The longer the lead in and out, the less cars are prone to braking suddenly at the last minute, something which would slow things down even more.

In terms of how much this all slows you down, let’s look at some figures. Let’s say the length of the speed restrictions is 5 miles give or take. And you would normally travel at say 77mph. Let’s say instead that you are restricted to an average speed of 40mph (speed limit plus 10% = 44mph, but let’s assume slower vehicles slow you down a bit).

So,
time taken to travel 5 miles at 77mph is: 3 minutes 53 seconds
time taken to travel 5 miles at 40mph is: 7 minutes 30 seconds

So this scheme would slow you down by about 3 minutes 40 seconds: not exactly a huge hardship.

Let’s hope they build bridges better than they build wooden fences.

Third time luck.