Background and Approach
LOS+ is a hybrid tool that implements two different multi-modal level of service (MMLOS) methodologies. The automobile LOS component of the analysis tool is consistent with the NCHRP Project 3-70 methodology, while the pedestrian, bicycle, and transit LOS components are consistent with the methodologies from in the Highway Capacity Manual 2010 (HCM2010). The analysis tool was developed as a link-based evaluation tool, which only analyzes the MMLOS along the roadway segment and not the intersection. This hybrid approach is less data-intensive than the full HCM2010 methodology and produces results that generally reflect pedestrian, bicyclist, and transit rider perceptions of service along a roadway.
NCHRP Project 3-70 provided the basis for the MMLOS methodology adopted in the HCM2010. However, there are some significant differences between the NCHRP and HCM methodologies. The auto LOS methodology in the HCM is more robust, but requires more input data and is computationally intensive. The HCM2010 methods for pedestrian, bicycle and transit LOS are very similar to that of NCHRP Project 3-70, the main difference is that the HCM2010 algorithms are more computationally intensive and give greater attention to MMLOS operations at the intersection level. LOS+ was developed as a hybrid methodology tool; an approach which minimizes the data inputs needed while providing results that are consistent with the HCM2010 for active transportation modes.Click to email our LOS+ leader
LOS+ was developed to be a quick-response/sketch-planning tool that provides guidance in designing urban streets to better accommodate the four major travel modes. LOS+ is an appropriate tool for general planning projects such as specific plans, road diet studies, and corridor planning studies.
LOS+ is not intended to be used as a complete traffic operations analysis model because operations at the intersection level are not incorporated. Thus, LOS+ should NOT be used to perform transportation impact analyses for specific development projects. The methodology is not effective in determining improvements that would mitigate MMLOS impacts at the intersection level.
Comparison between LOS+ and other MMLOS software
Overall, LOS+ is:
- less data-intensive,
- less expensive to own (it’s free!), and
- able to produce results that reflect auto, pedestrian, bicycle, and transit user perceptions of service along a roadway.
LOS+ provides three separate input tabs where users are required to enter data in the light green shaded areas. Even though LOS+ was developed as a quick-response tool relative to other software, the methodology still requires extensive data collection to analyze MMLOS along roadways. Generally speaking, the MMLOS methodology analyzes four separate travel modes (auto, pedestrian, bicycle and transit), thus expect that the data collection and labor hours needed to complete an MMLOS analysis will be 3 to 4 times more compared to analyzing only auto LOS using traditional methods. The input tabs are summarized below.
General Roadway Segment Data
The “Input_SegData” tab allows users to enter the following roadway data:
- Segment length (ft) measured from upstream boundary intersection stop bar to downstream boundary intersection stop bar
- Speed limit (mph)
- Vehicle flow rate (vph)
- Pedestrian flow rate (ped/hr)
- Peak-hour factor
- Heavy vehicle %
- Intersection control
- If downstream intersection is signalized, enter the % of green time for the analysis direction in relation to overall cycle length
- Adjusted saturation flow rate (vphgl); 1,800 vphgl is a reasonable assumption for signalized intersections, however can also be calculated from software such as Synchro
- Does the downstream boundary intersection approach provide separated left-turn lane(s)?
- Average travel time (s)
- Average number of stops per vehicle, which can be determined in the field along with travel time data
- Average pedestrian free-flow speed (ft/s)
The “Input_XSection” tab allows users to enter the following roadway cross-section data:
- Sidewalk width (ft)
- Fixed object width (ft)
- Buffer width (ft)
- Shoulder parking width (ft)
- Bike lane width (ft)
- Vehicle travel lane width (ft)
- Median width (ft)
- Median type
- Pavement condition
- Parking occupancy (%)
- Proportion of sidewalk length adjacent to window display, building face, fence or low wall
- Is curb present?
- Is parking striped?
- Does buffer contain continuous barrier at least 3 ft high and average spacing of 20 ft or less?
The “Input_Transit” tab allows users to enter the following transit data:
- Number of bus stops
- % of bus stops with shelters and/or benches
- Whether or not the bus stop is located in a Central Business District (CBD)
- If downstream boundary intersection is signalized, estimate running time loss (min/mi)
- Are bus stops on near side of intersection?
- Number of bus routes on segment
- Frequency of each route (bus/hr)
- Load factor of each route (pass/seat)
- On-time performance (%)
- Average bus dwell time (s)
- Re-entry delay (s)
- Average passenger trip length (miles)
Like any other software or analysis tool, LOS+ has its set of limitations, which are listed below:
- Does not analyze MMLOS at intersections, only provides MMLOS results along the roadway
- LOS+ only analyzes one direction of travel and up to 5 roadway segments at a time
- LOS+ and the HCM2010 methodology in general works best when the segment boundary intersections are signalized or side-street stop controlled. The auto and transit LOS HCM2010 methodologies aren’t intended to analyze all-way stop or roundabout controlled boundary intersections.
- Pedestrian and bicycle methodologies cannot model grades in excess of 2%
- Does not model pedestrian over-crossings
- Analysis time period limited to 1 hour, LOS+ can analyze 15 minute increments with volume data converted to hourly flow rates
- Pedestrian LOS does not consider roadway crossing difficulties