There will be disappointment among campaigners that the county council has decided not to go for a blanket 20mph speed limit in Oxford.

It would have been simpler to have had 20mph signs at all the entrances to the city.

Drivers would have then been in no doubt that the limit existed everywhere.

But while the limit is desirable and acceptable in residential roads, it is probably unrealistic to expect it to apply to all the radial routes.

One downturn of such a system, however, is that it will need a plethora of signs.

At the entrance to every side road, there will need to be a clear indication to drivers that they are moving into and out of a different zone.

We thought the county council was keen to reduce street clutter.

Another question that has yet to be answered is - who is going to enforce the 20mph limit?

As a matter of policy, the police won't do it.

Does that mean we will have to put our trust in drivers to observe the law? Some hope.