Cambridge startup Block Avenue prepares to launch a Yelp for your neighborhood

By Scott Kirsner, Globe Columnist

On the Internet, you can dole out stars and write reviews for doctors, hotels, restaurants, and even your evil employer. Now there's a Cambridge startup, Block Avenue, that wants to collect your opinions about the street where you live. The site is set to launch next week, and after getting a sneak peek of the company's demo, I've got two thoughts: 1. It's very cool, and 2. It's destined to cause controversy.

Block Avenue has divided up the U.S. into 1.89 billion squares, each one with 300 feet on each side, says founder Tony Longo. (He's on the right in the photo, with director of engineering Drew Myers.) "Then, we went and we collected as much data as we could about each block," he says. That includes information about whether there's public transit, car-sharing, or bike-sharing locations; recent crimes and sex offenders who live in that block; amenities like gyms, parks, dry cleaners, grocery stores, and restaurants; and schools. "There are players out there who do each of those things on their own," says Longo, "but nobody has brought it together." Based on the information Block Avenue collects, its software algorithm assigns a grade, from A through F. As you zoom in and out on Block Avenue's map, the system calculates an overall grade for the area you're looking at, which shows up in the upper right corner. (See the screen shot below.)

Visitors to the site can also write reviews of blocks they live on, or are familiar with. They can also add even more information to Block Avenue's database, rating a block on matters like noise, cleanliness, traffic levels, and community spirit (all things which Block Avenue couldn't find in existing databases.) Longo says that user reviews and ratings will influence those automatic grades that Block Avenue assigns.

The company is focusing on three cities in its launch phase: Boston, New York, and Washington, D.C., and Longo says that during its testing this summer, the company has already gathered about 2,000 reviews from users in those cities.

Now, on to the potential for controversy. Longo has plans to overlay U.S. Census data about race, income, average age, and ethnicity onto Block Avenue's maps, which could upset people. (Though there are already sites like Mixed Metro that offer up some of that information.) Second, no homeowner will want to admit they live on a Grade D or F block, especially if they ever hope to sell their property, and so I predict there will be a natural tilt toward grade inflation. (I also think it will be a challenge to keep boosterish real estate agents from writing gushy reviews about the areas they represent.)

Longo, as it happens, was previously the founder of the online brokerage CondoDomain, and he acknowledges the potential for problems. "We will have a very careful eye on real estate agents, developers, and property managers," he says. (CondoDomain was acquired by Better Homes Realty last month.)

The site plans to make money by licensing its data to real estate sites — think Zillow and Trulia — as well as selling a service to realtors that would enable them to create reports about specific neighborhoods for their customers. There also will be advertising on the site, Longo says.