Google Maps doesn’t know everything. Baltimore has its own map sets to help residents and tourists find places to eat and things to do, see the areas shaded by tree canopies and the locations of traffic cameras around the city -- among many others.

City agencies regularly use mapping internally, and Baltimore has created dozens of maps for various city functions over the years. So in December of 2011, the city decided to publish a maps gallery to make its growing collection more accessible to the public, said Brad Chranko, who works in the Enterprise Geographic Information Systems (eGIS) Department, part of the Mayor’s Office of Information Technology.

Most of the maps were created to meet agency needs. The residential parking permit lookup, for instance, helps the city parking authority conduct its permitting program. Other apps were created by the eGIS department to address perceived needs. The city’s aerial view over time map is one example of this, as it shows satellite imagery of the city taken from two different years and compares them side by side to see how the city has changed.

As for the public, residents and tourists can use the Baltimore Shortlist map to find the city's best restaurants, attractions and landmarks; bicyclists can use the Flattest Route Finder to avoid hills on their planned journey; and residents can look up their trash and recyling days, to name a few. The gallery features more than 30 map applications that provide functionality to the public, and showcase the work of the city’s enterprise geographic information systems (eGIS) department.

The gallery gets about 2,000 hits each month, and averages about 100 visits per weekday, according to the department. When there’s a storm, usage goes up as users search for storm-related maps.

“The users are a mix of  city residents, current and prospective, looking to gain information that may have an impact on their home or neighborhood," Chranko said, "as well as city business owners, city planners, developers, the city’s 311 operators needing quick references, and researchers from universities, foundations or nonprofits."

Internally, maps are used by many agencies, including those with public safety functions. “The maps used by public safety are predominantly the 311 Service Request Calls, Snow Zones and Emergency Routes, Inundation Zones, Emergency Evacuation Routes, and Evacuation Shelters,” Chranko said. “They use them to help better direct citizens to find city resources during emergencies, and also provide a more spatial concept in order for the city to mobilize more efficiently during emergency situations.”

City agencies can adjust their operations based on the information gleaned from maps like 311 Service Requests, Chranko said. During traffic or street light outages, snowy weather, or floods, safety officials can use the maps to reroute officers’ patrols. Environmental police who patrol the city’s reservoirs can use service request maps to track things like water odor complaints. The city can even use triggers in its GIS to relay text messages and emails to the appropriate officials when a complaint falls within a certain radius of a critical facility.

“We wanted a central gathering place for all of our publicly available interactive mapping applications,” Chranko said. “The majority of these applications can be found in several locations across the city’s website. Although they are linked to or embedded in the agency’s or project page they support, we wanted to also have them in a central place so that the public can easily discover what eGIS has to offer them, thereby maximizing their exposure and usage.”

Colin Wood Colin Wood  |  Staff Writer

Colin has been writing for Government Technology since 2010. He lives in Seattle with his wife and their dog. He can be reached at cwood@govtech.com and on Google+.