BLOS/PLOS Before & After Calculator Form
Created by Ed Barsotti, League of Illinois Bicyclists, 630-978-0583, ed@bikelib.org
To calculate Bicycle Level of Service (BLOS) and Pedestrian Level of Service (PLOS) before and after
a particular roadway project, fill out the following for the typical cross-section.
Results will pop up in a new window.
Default values will be used for any fields left empty.
Some details on the input fields and their ranges are here.
Further information and references on these measures are here.
BLOS/PLOS Data Input Fields
The following provides further information on the BLOS and PLOS data inputs. See the
references for more.
Roadway parameters will often change, and averaging could be done depending on the situation. In general, try to select a typical cross-section.
| Through lanes per direction: | Do not include
medians, turn lanes, or continuous-left-turn lanes. |
| Width of outside travel lane, to outside stripe (in feet): | Width of right-most travel
lane, excluding striped paved shoulders, bike lanes, and marked parking stalls. |
| Paved shoulder, bike lane, OR marked parking area, outside lane stripe to pavement edge (in feet): |
Besides a paved shoulder or a bike lane, this width
may also be marked (striped or hashed) parking stalls. For diagonal parking, use the perpendicular distance from the
end of the parking stripes to the pavement edge.
This calculator does not work when there are BOTH bike lanes and parking stalls
- please see the
reference for this case. |
| Bi-directional Traffic Volume (in ADT): | Daily average. Assumed Directional factor
(0.565) and Peak Hour Factor (0.091) values are used in a conversion to peak 15-minute volume. |
| Percentage of heavy vehicles: | As defined in the Highway Capacity Manual. |
| FHWA's pavement condition rating: | Use the actual "before" value. Unless "before" is higher
than "4", use "4" for the "after" value to reflect the average over the lifetime of the road. |
| Percentage of road segment with occupied on-street parking: | Exclude driveways.
Either one side or an average of both sides may be considered at a time. |
| Percentage of segment with sidewalks: | Again, either one side or an average
of both sides may be considered. |
| Sidewalk width (in feet): | If a sidepath bike trail exists instead of a sidewalk, use
its width. |
| Sidewalk buffer/parkway width (in feet): |
Average distance from pavement edge to sidewalk edge.
Include any gutter pan width. |
| Buffer/parkway average tree spacing (in feet): | Between tree trunks. |
Model parameter ranges
The BLOS model was developed using roads with the following parameter ranges:
- Through lanes per direction - 1 to 3 (2 to 6 lane roads)
- Width of outside travel lane, to outside stripe - 10 to 16 feet
- Paved shoulder or bike lane, outside lane stripe to pavement edge - 0 to 6 feet (no rumble strips)
- Bi-directional traffic volume - 550 to 36,000 ADT (Average Daily Traffic)
- Posted speed limit - 25 to 50 mph
- Percentage of heavy vehicles - 0 to 2%
- FHWA's pavement condition rating - 5 (very good) to 2 (poor)
- A wide range of development types and parking conditions
(Be aware of model use outside these ranges, particularly for paved shoulders much over 6 feet and more than a few percent heavy vehicles.)
The parameter ranges used in developing the PLOS model include:
- Through lanes per direction - 1 to 2 (2 to 4 lane roads)
- Bi-directional traffic volume - 200 to 18,000 ADT (Average Daily Traffic)
- Traffic speeds - 15 to 75 mph
- Percentage of heavy vehicles - 0 to 3%
- Ranges of development types, road widths, paved shoulders and bike lanes, on-street parking percentages, sidewalk widths and sidewalk buffer widths and types
Top of page
LIB home page
Created
2003-10-15
Cosmetic revisions 2004-05-03
Lee Pirtle,
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