Introduction

Our online public space permit system (TOPS) holds information on a variety of different permit types. The type which permits blocking off lane(s) or the entire roadway is called an Occupancy permit; it is called this because the user is being permitted to occupy a portion of the public right-of-way. In this case, it is a portion of the roadway.

Processing Lane/Road Closure Data

Each night, DDOT extracts permit information from TOPS and publishes this as a RESTful ESRI map service. In TOPS, a permit is typically associated to either an address or a block range. For the map service extract, each permit location is reduced to a single, representative point even though lane and road closures which are typically expressed as linear features. This single point is then snapped to the DDOT Centerline roadway GIS, where a multitude of roadway attributes are then joined. Additionally, each permit point is enriched with a variety of local DC geographical information (for example the Ward, ANC, census tract, etc).

The result is a summary of the occupancy permit that has also been enriched with roadway and a ton of other data that makes mapping and downstream analysis easier.

Issues with Road Closure Permit Data

There are some known issues that prevent the closure data from being more accurate. We have been informed that all or most of these issues should be resolved in a future version of TOPS.

The TOPS permit-related closure data has indeterminate start and end dates/times. Permits have a date range that the permit is valid for (IssuedDate and ExpirationDate), but this may not correspond to the permit holder's actual road/lane closure begin and end date. Currently, a permit holder is not obligated to tell DDOT precisely when the will begin and end the closure.
The geographic bounds/length of the closure are ambiguous. The point in the map service is an approximation of the permit location, with the permit's widths and length. The precise begin/end point of the closure is not represented in the data.
There are several other jurisdictional entities in DC that can institute road closures. They may or may not be communicating these to DDOT in a timely matter.

US Park Police
US Capitol Police
National Park Service
Architect of the Capitol
Likely others...

Update frequency

The data are refreshed each night a little before midnight.

DC Open Data

Occupancy permit data can be found on DC's extremely awesome Open Data portal:

https://opendata.dc.gov/datasets/occupancy-permits-via-ddot-tops

REST Service URLs for Lane/Road Closure Data

Map service endpoint is here: https://maps2.dcgis.dc.gov/dcgis/rest/services/DDOT/TOPS/MapServer/1

Query endpoint is here: https://maps2.dcgis.dc.gov/dcgis/rest/services/DDOT/TOPS/MapServer/1/query

Road closures

To filter and ensure that you are getting only active/live permits for road closures, you should pass the following parameter constraints:

Status = 'Issued'
ExpirationDate >= Current_Day
IsRoadClosed = 'Y'

Here is an example query for this request

Lane closures

To filter and ensure that you are getting only active/live permits for lane closures, you should pass the following parameter constraints:

Status = 'Issued'
ExpirationDate >= Current_Day
Search any of the below attributes for values > 0:

CurbLaneLength
AlleyLength
BikeLaneLength
IntersectionLength
TravelLane1Length
TravelLane2Length
TravelLane3Length
TravelLane4Length

Here is an example query for this request

Browser not supported