This polygon layer contains the two elective districts for congressmen in Cambridge in the United State Congress. This layer was created for general use by the Cambridge Election Commission and for public distribution. There are two congressional districts in Cambridge, one of which is in the middle of another one.

For more information and download links see:
http://www.cambridgema.gov/gis/gisdatadictionary/elections/elections_congressionaldistricts.aspx

Fire Hydrants are maintained by the Engineering group at the Cambridge Water Department, Hydrants are also monitored by Cambridge Fire Department. Used for public safety, mapping, and water distribution.

For more information and download links see:
https://www.cambridgema.gov/gis/gisdatadictionary/infra/infra_hydrants

This layer contains two polygons representing the city's Historic Districts, Fort Washington Historic District and Old Cambridge Historic District. Historic Districts are groups of buildings, structures, and their surroundings that are architecturally and historically distinctive. Exterior changes to buildings within Historic Districts are subject to review by the Historical Commission made up of residents appointed by the City Manager.

For more information and download links see:
http://www.cambridgema.gov/GIS/gisdatadictionary/Historical/HISTORICAL_HistoricDistricts.aspx

This point layer contains the police stations within the City of Cambridge.

This point layer is are all of the Cobrahead street lights which will be replaced throughout the summer of 2014. There are other types of lights in the City which are not included in this GIS layer. Decorative street lights which will be replaced in 2015, and lights owned by others (DCR, Universities, & private) have not been verified for accuracy yet and will be included in a future update of this layer.

This layer contains five polygons representing the city's Neighborhood Conservation Districts (NCDs). Conservation districts are groups of buildings and their surroundings that are architecturally and historically distinctive. Exterior changes to buildings within NCDs are subject to review by NCD commissions made up of residents appointed by the City Manager. The GIS data layer was created in 2000 from paper documents. Cambridge designated its first NCD in 1984, following City Council legislation the year before allowing NCD establishment.

For more information and download links see:
http://www.cambridgema.gov/GIS/gisdatadictionary/Historical/HISTORICAL_NhoodConservationDist.aspx

This layer contains point features of Youth Centers in Cambridge. Created for general use by City staff. Used for both mapping and specific identification of buildings with a similar use.

For more information and download links see:
http://www.cambridgema.gov/GIS/gisdatadictionary/Landmark/LANDMARK_YouthCenters.aspx

This layer was created for general use by the Cambridge Election Commission and for public distribution. Cambridge wards and precincts which designate where voters will vote. This polygon layer contains 11 wards and 33 precincts within the City of Cambridge. These were adjusted in 2011 from the 2010 U.S. Census.

For more information and download links see:
http://www.cambridgema.gov/GIS/gisdatadictionary/Elections/ELECTIONS_WardsPrecincts.aspx

This dataset contains the Average Daily Traffic counts and AM and PM peak hour Traffic counts measured on various road segments in the City of Cambridge from 1972 to 2017. The counts in this data set reflect only vehicle counts. An Average Daily Count measures the number of vehicles for an entire day, or an average of several days. Automatic Traffic Recorders (ATRs) log every vehicle that passes in each direction and this data is used to calculate Average Daily Traffic volumes and AM and PM Peak Hour Traffic Volumes for the street. The Peak Hour is average highest number of vehicles recorded during the morning and evening peak hour. Not all streets have the same peak hour. For example, the peak hour for one street could be 5 pm to 6 pm, whereas a peak hour for another street could be from 5:15 pm to 6:15 pm. The peak hour for a street can also change from day to day. When counts are done for several days, the Peak Hour count is the average of the highest peak hour over those days.
Automatic Traffic Recorders (ATR’s) are rubber hoses temporarily affixed to the street. When a vehicle passes, a pulse of air passes through the hose and triggers an air switch in a recording device on the roadside. The recorder device is a small steel box powered by a battery. Air switch triggers are stored on board and later downloaded to a computer. Note: Traditional and older ATRs were not able to record bicycles, however, more recent ATR’s (past 5 to 10 years) have been able to record bicycles that pass over the recorder.

This polygon layer contains the City of Cambridge daily street cleaning districts. Created to delineate the daily street sweeping districts in Cambridge. The district attribute in the layer corresponds to the street cleaning schedule posted on the Cambridge DPW website.

For more information and download links see:
http://www.cambridgema.gov/gis/gisdatadictionary/dpw/dpw_streetsweepingdistricts.aspx