What is a Fishbone?
Fishbones identify address points that fall within the range of the associated road centerline with matching attributes. In the Fishbone Markup files, FB01-3 are the fishbones. These markup lines will also indicate if the fishbone is on the right or left side of the road centerline.
How are Fishbones Impactful?
For data, fishbones simply indicate when an address point can locate a road centerline. In the real world, fishbones tell us when an address point can be routed to a road centerline. For efficient routing, fishbones should create perpendicular lines, directly in front of the structure so that a first responder can quickly respond to an emergency.
In an NG9-1-1 environment, the absence of a fishbone tells us that first responders would not be able to route to the address point (AP Not Reflected in RCL anomaly). When there is more than one fishbone coming from a single address point, going to multiple road centerlines, it indicates that there will be issues with the first responders routing to the address (AP Maps to Multiple RCL anomaly). When there are fishbones that cross one another, these may confuse the first responder because the addresses are misordered and may be routed further away from the structure (AP Misordered Along RCL anomaly).
Reducing anomalies and creating perpendicular fishbones will aid in the transition to NG9-1-1 by getting the GIS data ready to be NG9-1-1 call routable.
Fields Used for Drawing Fishbones
Site_Address_Points | Road_Centerlines |
add_number | adnumpre_l |
st_premod | adnumpre_r |
st_predir | fromaddr_l |
st_pretyp | toaddr_l |
st_presep | fromaddr_r |
st_name | toaddr_r |
st_postyp | st_premod |
st_posdir | st_predir |
st_posmod | st_pretyp |
state | st_presep |
county | st_name |
inc_muni* | st_postyp |
uninc_comm | st_posdir |
st_posmod | |
| parity_l** |
| Parity_r** |
| state_l |
| state_r |
| county_l |
| county_r |
| incmuni_l* |
| incmuni_r* |
| uninccom_l |
| uninccom_r |
If the Inc_muni (and incmuni_l/incmuni_r) field is populated with “Unincorporated” then the validation will then compare the Uninc_comm (and unincom_l/uninccom/r) fields.
**The parity_l and parity_r fields are used only if they are populated. If these fields are not populated, the validation will use the RCL to and from the range on each side to determine the parity for each side of the RCL.
Fishbone FAQ (Frequently Asked Questions)
How are fishbones created?
Fishbones are created by drawing a line between the address point and where it falls along a road centerline’s range. This is done using the Address Point location and attributes and the Road Centerline location and attributes and not by using a geocoding service.
How are the Incorporated Municipality and Unincorporated Municipality fields used when creating fishbones?
If the incorporated municipality fields are populated with “unincorporated”, the fishbone logic will then compare the unincorporated community fields between the Address Point and Road Centerline to determine if there is a match. Otherwise, the unincorporated community fields are not used in the comparison.
How are the Road Centerline Parity fields used?
If the parity left and parity right fields have values, the fishbone logic will use those values to match Address Points to Road Centerlines. If the parity fields are null, the fishbone logic will use the road centerline range values to determine the parity of each side of a Road Centerline.
Does the capitalization of my attributes matter?
Capitalization of the attributes for both the Address Points and Road Centerlines does not matter in the fishbone validations, whether the values are all lowercase, uppercase, or mixed case.
What factors prevent fishbones from being created?
Road Centerline ranges from high to low
Mismatched attribution between the fields being compared for the Address Points and Road Centerlines
Example: SW GULF BLVD. vs. SOUTHWEST GULF BLVD
Example: Unincorporated Inc_Muni vs. Null Inc_Muni
Example: Jefferson County vs. Jeffs County
Address Points located on the wrong side of the street
Incorrect parity values for the Road Centerline segments