No one seems to have picked up this comment but I seriously agree!!
in this country we have a system of rights of ways established over many centuriies by use of roads and paths pedestrians animals (including horses and driven stock) and by horse draw vehicles. This is system is enshrined in law (Highways act 1980) It is only in the 20th century that the increased use of motor vehicles has meant the horse is much less prevalent on the roads and only used on roads for recreational purposes.
There is a long an establish right to ride (horses) on roads just cos car drivers find them an inconvenience they should not be banned.
Pedestrians cyclist etc on the carriage way can present just a similar hazard to motorists. Horse may cause additional hazard if startled this is not necessarly the horses fault but this can be caused by the lack of care by motorist. You pass horses carefully just in the same way you check for pedestrian at a zebra crossing it's a matter of safe driving.
What could be worth while is testing licencing all road users horses thier riders cyclist etc. A horse and rider should only be allowed on the road if propery insured schooled and tested.
Personally I'd
ban joggers
First. There are lots of other places to exersise without causing a hazard on the road
Second. Run on the road when a verge is available.
Third. They do not take due care and attention of other road users. Often run with thier back to traffic where they are unable to monitor and be aware of traffic to minimise risks to them selves and other road users. There intention to run a a steady place means thay do not modulate thier road use to minmise inconvenience and hazard to other road users