a) Public Benefits
I think it's difficult to establish a formula outside a project on the table, but I have some guidelines that could repeatedly be applied. First, whatever obligations are agreed between the city and an applicant must apply to successor owners.
Second, whatever obligations for public benefit must continue at least as long as the project, or use. An example of failure in this was the agreement between Stanford University and the City of Palo Alto where in return for increasing development rights in the Stanford Industrial Park, Stanford built public soccer fields at the corner of page Mill Road and El Camino. That's a great example of public benefit. However, the agreement to provide the soccer fields if limited to 30 years, while the extra office entitlement is in perpetuity, regardless of the impacts after 30 years.
Another example is the sales tax agreement Sun Microsystems made with the city to domicile their cooperate sales HQ in Menlo park at the Sun campus. In return for development rights, the sales tax agreement provided the sales tax for 10 years.
b) Mitigations of adverse consequences of development
Part of major project approval process is conformance to CEQA (California Environmental Quality Act) review. In some ways even what is reviewed is discretionary. In a nutshell, CEQA is applied to discretionary projects reviewing impacts of traffic, air, and water ? yielding a grade of no impact, minor, significant or non-mitigatable. A CEQA report will (should) present options for mitigations.
The important aspect is that there must be a nexus between the identified problem and the potential mitigation. For example, proposing a playground as mitigation for a project whose traffic increases delays at an intersection from grade 'D' to 'F' doesn't solve the problem. Providing a stoplight to organize flow does have a nexus to the problem.
When a project has too many people, hence requires too many parking spots, many times the non-provided parking is in 'landscape reserve.' I always considered this a cop-out and only mitigated the approval process. I've never seen greenery pulled out to accommodate the cars especially since there was also a landscape requirement for the project.
In the mitigation toolkit for traffic problems are shuttles, train passes and other options like the white corporate busses.
c) Abandonment of right-ways
The city and utilities maintain right-of-ways for access that traversing private property. These limit use of the space by the owner. Occasionally a project asks the city of abandon a right-of-way. It's a discretionary decision. Abandonment has the potential financial enhancement to the owner especially if it enables an increase in buildable footage. Discretionary abandonment by the city may have great value to the owner. It's an opportunity, perhaps, for applying public benefit.
d) Public space
In my view public space is a great benefit. In our world the iconic version of that is the plaza at Café Borrone and Kepler's Bookstore. It's fosters interaction with others. We somewhat blew in with the downtown specific plan when permitting private balconies to be public space. This detail wasn't in the spirit of the 'public' aspect.
e) % for Art
One way to distinguish Menlo Park over other cities is to encourage display of significant artworks in significant spots. I thought ? and we've lost this opportunity ? to reserve open spots one ach block of El Camino for art installations. I'd call that a public benefit.
At one time we had a statutory '%-for-art' requirement in commercial development. This program had its problems, but the problems were not with the concept ? it was execution.
With all the development both underway and proposed, art should definitely be in the toolkit of options.
Finally, the city always has the option to say no. There's no requirement for the city to say yes to proposals that don't make sense. This enables the City to be a tougher negotiator.