Apple has published a support document on its website confirming that it has been using a fleet of vehicles to collect street-level imagery for Apple Maps. Apple outlines that it will blur faces and license plates on images, as Google Maps does for Street View, and lists where Apple Maps vehicles will be driving in the United States, England and Ireland between June 15 to June 30.

Apple-Vans

"Apple is driving vehicles around the world to collect data which will be used to improve Apple Maps. Some of this data will be published in future Apple Maps updates. We are committed to protecting your privacy while collecting this data. For example, we will blur faces and license plates on collected images prior to publication."
Apple has been driving around fifth-generation Dodge Caravans equipped with LiDAR camera equipment on the roof to collect street-level imagery in the United States, starting with major cities and metropolitan areas in the south, northeast and midwest regions of the country. The mapping vehicles have been spotted in at least a dozen states to date as they continue moving further inland. 
Apple-Maps

Since then, using verified photos with GPS metadata, we have confirmed Apple Maps vehicle sightings in Atlanta, Chicago, Dallas, Los Angeles, Phoenix, San Francisco and many other areas. Many of those locations are listed below. 

Anaheim, California 
Atlanta, Georgia 
Chicago, Illinois 
Dallas, Texas 
Las Vegas, Nevada 
Los Angeles, California 
Maui, Hawaii 
Miami, Florida 
New York City, New York 
Orlando, Florida 
Palo Alto, California 
Phoenix, Arizona 
Salt Lake City, Utah 
San Diego, California 
San Francisco, California 
Sunnyvale, California 

Apple confirms many of these locations in the support document, while adding Oahu, Boston, Detroit, St. Louis, Seattle, Tucson and surrounding counties as additional U.S. regions it will be surveying in the second half of June. Apple Maps vehicles will also head overseas to collect street-level imagery in Birmingham, Dublin, Essex, Kent, London and several other cities and counties in England and Ireland. 

The collection of street-level imagery is part of Apple's larger shift towards in-house mapping data, in order to reduce its reliance on third-party companies such as TomTom, which has provided data for Apple Maps since it launched. Apple is also allegedly taking photos of businesses, storefronts and other points of interest to replace photos currently provided by Yelp and other third parties.