Provided it could be done well I think this is a fabulous idea.
Four metres wide sounds adequate but this width must be maintained as much as possible with an absolute minimum of obstructions.
Access to the route must have smooth radius curves with no sharp bends or drops. The route must have a feeling of subjective safety for its entire length. It must be cyclists only and this must be clearly and unambiguously signed.
The original artist’s impression from the RBK bid document looks much better than the picture from the LBC website. The path is straighter, it’s closer to the bank, has a clear delineation between the cycle path and a walkway for access to moored boats. The cycle path must not be “shared use”.
Any riverside route must not preclude improvements to routes through the town centre (Wood Street, Clarence Road etc.) or the need for segregated cycle tracks along Portsmouth Road. This must not be seen as THE north-south route. In fact a riverside route would encourage people onto their bikes and would only make the case for clear continuous routes through the town centre even stronger.
Done properly this really could be a flagship scheme that draws people to cycle in and around Kingston. The routes approaching Kingston along the river are quite good. Once you hit the town centre though you are rather left to your own devices. This route would make arriving in Kingston by bike a pleasant experience and give it a real Wow! Factor.
It’s a valuable route in its own right but the real value could be in putting Kingston on the map as a cycling town.