Transportation Conundrum: Cash-strapped cities worldwide face difficult decisions.

Around the globe, cities are trying a variety of measures to tackle transportation-related challenges. However, in tough economic times, dwindling budgets force tough choices about where to invest time and money.

I thought a great deal about this during my recent visit to Barcelona, Spain, where I participated in the Smart City Expo and moderated a panel on lessons from Spain’s deployment of electric vehicles. This is, after all, a country with trying economic issues. Spain holds the highest jobless rate among industrialized countries. Still, it is investing heavily in infrastructure and incentives for the adoption of electric vehicles, a technology with an up-front premium that makes its purchase difficult for most employed people. That may beg this question: Is public transit a better investment when many Spaniards are struggling just to get by?

Barcelona already boasts a strong public transit system. Several buses, a robust metro system and a seemingly popular public bicycle program make mobility easy. In a current effort to develop a casebook of global EV activities, the Clean Energy Ministerial found that in Barcelona, only about 24 percent of the citizenry relies on personal transportation for its daily commute. Of the remaining citizens, about 42 percent bicycle or walk and 34 percent take public transport.

Still, the roads are bursting with cars, so the city has created an Urban Area Protected Atmosphere in its effort to reduce air pollution. It has seen success: By 2015 the city estimates a 20 percent reduction in nitrogen oxides emissions and 16 percent reduction in particulate matter.

Is the electric vehicle the solution to these problems? It’s not a silver bullet, but EVs can still be a part of the answer for cities like Barcelona that have multiple transportation options.

As suggested in Rocky Mountain Institute’s Reinventing Fire, we should begin looking at transportation in terms of a portfolio of mobility options, each chosen based on their aptness for the destination desired. When cities consider the intermodal nature of their transportation systems, they are then able to identify areas of opportunity for vehicle electrification—placing charging infrastructure in parking lots at transit hubs or working with local car-sharing programs to electrify a portion of those fleets.

It should also be noted that, though we speak a great deal about electric cars, there are excellent opportunities to electrify other forms of transportation. For instance, 40 percent of Barcelona’s personal transportation consists of two-wheeled motorized vehicles—scooters and motorcycles.

To encourage adoption of electric vehicles, cities can employ a number of strategies: fund the installation of public charging infrastructure; purchase vehicles for their fleet, and offer a number of financial and non-financial incentives (tax credits, free parking, and HOV lane access, to name a few). Indeed, many cities around the world are doing just that. RMI’s Project Get Ready cities have made great strides in EV readiness, as have cities including Barcelona.

But a city can do only so much. The total-cost-of-ownership benefits exhibited in EVs are attractive to some commercial fleets, but consumers’ car-buying decisions are often based on emotional impulses more than logical long-term calculations. Therefore, cities should take stock of their options and weigh them according to resource demand and anticipated impact. In other words, which measures will have the most bang for the buck?

Here in the U.S., where we have fewer public transit options, vehicle electrification offers an alternative that mitigates pollution, reduces oil dependence and supports a growing, job-creating industry. But there is much to learn from Barcelona and other cities, such as Stockholm or Amsterdam. Through exchanging lessons learned in EV readiness, cities around the world will find new and innovative approaches to mobility as a whole.