(a)
A county and a city or cities may join in the acquisition of rights-of-way, construction, maintenance, improvement, or repair of bicycle routes or paths, or portions thereof, located within or without the city or cities.
(b)
The cost or expense thereof shall be apportioned among the county and the city or cities as the legislative bodies thereof determine by agreement.
(c)
The authority and responsibility for the acquisition and work shall vest in the county or in the city or cities, or in both, as provided in the agreement apportioning the cost or expense thereof.