The tent protesters encamped on Tel Aviv’s Rothschild Boulevard have only to look up if they wish to see a major cause of the country’s housing crisis, one that has so far been virtually ignored.If they raise their eyes to the iconic, white-washed Bauhaus structures that line the Boulevard, they will find that they need only look two, three or four stories high.And that is exactly the problem. Tel Aviv is a low-built, sprawling metropolis. One can forgive the original builders for this planning error. The founders of Ahuzat Bayit, the first Tel Aviv neighborhood, which included Rothschild Boulevard, laid out their original street plan for 60 families in 1909. Little did they dream that within a century their neighborhood would lie at the center of a conurbation housing over three million people.But the failures of later generations of urban planners are much less excusable.Over the past 20 years, there has been a proliferation of suburban dormitory communities based around single-family villas. These developments, and the commuters they generate, have contributed significantly to traffic congestion in the Gush Dan region.With a density of 7,700 people per square kilometer, Tel Aviv is far behind international urban magnets such as Paris, which has an urban density of 25,000 people per square kilometer, or Manhattan, where urban density is more than 35,000 per square kilometer.And Tel Aviv is Israel’s densest big city. In the Gush Dan region as a whole, there are only 2,100 people per square kilometer.Such low urban density leads to major problems. First, it is a prime reason behind the dearth of affordable housing in the Tel Aviv area. Residential units within easy reach of Tel Aviv are too few and too expensive.Second, it renders the city very hard to serve with adequate public transit, and makes people heavily dependent on private vehicles.This car dependency, in turn, feeds a slew of other problems. It makes people waste hours each day in traffic jams(a recent study showed that people who commute daily into Tel Aviv spend the equivalent of five weeks out of every year sitting in their cars).It worsens social inequality: If the automobile is the only effective way to get around, then that puts many job and recreation opportunities beyond the reach of those who cannot afford the NIS 3,000-plus per month needed to keep a car on the road.And private car dependency perpetuates the national dependency on foreign oil imports.In a country as small as Israel, it is madness to build towns and cities more sprawling than most in the Western world. As we are fond of telling people, Israel is roughly the size of New Jersey. It seems that we have taken that comparison a little too literally. If we continue building suburbs as if this were New Jersey, we will pave over our remaining open spaces and reduce the country to gridlock.THERE IS a better way. Indeed, there are several.In cities like Paris, Barcelona and New York, high urban density engenders a critical mass of economic and cultural innovation.The New Urbanism movement in the US has developed mixed-use models for urban regeneration based on creating walkable downtown areas that bring workplaces, recreation and shopping within reach of all residents.Most excitingly, China and South Korea are responding to their population growth and urbanization by developing eco-cities that combine high-density building, innovative public transit and efficient use of resources with beautiful parks and open spaces.Israel has both the need and the know-how to become a world leader in developing and implementing such sustainable city solutions.Doing so will help solve its acute housing, transportation and energy challenges, ensure a better quality of life for its urban residents, and position the country at the forefront of a major 21st-century industry.The Trajtenberg Committee, charged with addressing the housing protests, should endorse a plan for implementing sustainable city solutions on a large scale in the Gush Dan area over the next five years, creating high-density urban development, vastly improved public transit and mixeduse, walkable neighborhoods. This is the most effective and holistic step that can be taken to meet the housing protesters’ demands. It is the solution that lies, literally, in front of the protesters’ eyes.The writer is an economist working in Israel’s renewable energy industry. He also serves as an economic adviser to the Green Movement.