We have a lot of problems with the 'serious' (aka Lycra clad) cyclists on one particular busy B road near us. It's an ancient road so quite narrow in places with high banks. It has no cycle track and goes though several villages. I can understand why it's so popular as it's undulating with gentle bends and a nice fast ten mile stretch so it's often used for events. These are often not publiced, there are no warning signs and a lot of teams use the route for practice at all times of the week.
They ride in clumps, no signalling, weaving all over the place and cannot be seen on the many blind bends and seem oblivious to other road users. The other road users - slow pedalling cyclists, the occasional horse rider, tractors, harvesters, sugar beet/pea/spud lorries (they don't hang about), white van man and cars are there under sufferance as far as they're concerned.
I just wish it could be closed to all other traffic for say Sunday mornings (except through the villages obviously), so the cyclists can have free rein at a set time. It's so dangerous and there have been accidents.
Sorry, this is of the subject a bit. Just a grouse. We don't have cycle lanes. There are some under used ones in Norwich and the council is spending a fortune putting in some cycle only routes. It'll be interesting to see if they will be used.