This report computes, for a selected highway or group of highways, the total number of lane-mile-hours operating at each LOS value during a typical morning or evening commuter period. (For a quick summary of LOS performance ratings, click here.) A bar chart is then produced, with lane-mile-hours as the 'Y-axis' parameter, and with a separate bar for each surveyed year along the X-axis. LOS data are 'stacked' onto each bar such that, if performance ratings generally decline between surveyed years, less of the bar is colored green (for LOS values A, B or C), and a greater percentage of the bar is colored yellow, orange or red (for LOS values D, E or F, respectively). Once side-by-side bars have been generated, this report makes it easy to see if, given recent levels of investment, the selected subsystem or specific highway has been keeping pace with demand or falling behind. If the user elects to analyze the first or third hour of the morning or evening analysis periods, peak-hour spreading will be evident in these displays (as the green and yellow parts of the bars decrease while orange and red parts increase).
A suitable performance measure at the macro level to gauge peak-period traffic conditions is to sum the number of lane-mile-hours (lmh's) operating at each LOS rating during a specified time period. For example, for each survey year, during the three-hour morning and three-hour evening peak periods, each link has one LOS rating for each hour (six ratings altogether). Because each link is comprised of a fixed number of lane-miles (segment length multiplied by the number of lanes), those lane miles can be grouped by LOS rating and then summed. If the user wants to examine just one hour, then the number of lane-mile-hours equals the number of lane-miles; however, if the user wants to compare two- or three-hour periods, the total number of lane-mile-hours is double or triple the number of lane-miles (respectively).
| Highway Segment |
Direction | Length (miles) |
LANES | Lane- miles |
LOS 4-5 PM |
LOS 5-6 PM |
LOS 6-7 PM |
| 1 | EB | 1.5 | 3 | 4.5 | A | A | A |
| 1 | WB | 1.5 | 3 | 4.5 | D | D | D |
| 2 | EB | 2 | 3 | 6 | B | B | B |
| 2 | WB | 2 | 3 | 6 | F | F | E |
| 3 | EB | 1.3 | 3 | 3.9 | B | C | B |
| 3 | WB | 1.3 | 3 | 3.9 | E | E | D |
In the eastbound direction, segment 1 (comprised of 4.5 lane-miles) operates at LOS A for all three hours. Therefore, the number of lane-mile-hours operating at LOS A would be 4.5 x 3 = 13.5 lmh's. In the other direction, there would also be 13.5 lmh's operating at LOS D.
Adding these up for the entire table produces a total of 86.4 lmh's for the three-hour evening survey period, broken down by LOS as follows:
| Segment | Direction | LOS A | LOS B | LOS C | LOS D | LOS E | LOS F |
| 1 | EB | 13.5 | |||||
| 1 | WB | 13.5 | |||||
| 2 | EB | 18 | |||||
| 2 | WB | 6 | 12 | ||||
| 3 | EB | 7.8 | 3.9 | ||||
| 3 | WB | ___ | ___ | ___ | 3.9 | 7.8 | ___ |
| Total lmh's | 13.5 | 25.8 | 3.9 | 17.4 | 13.8 | 12 |
The totals across the bottom can be 'stacked' into a single bar and colored by LOS, and displayed adjacent to bars from other surveyed years, to form charts suitable for displaying macro-level changes over time.
These report graphics may be printed or saved to an html format directly from the browser, for later viewing with your browser. There are also two options for exporting. The first option is to capture your screen display directly using the 'Print Screen' key on your keyboard; then use the 'paste' command (control-V) to insert the screen display into documents created by other application programs (such as Microsoft Powerpoint or Adobe Photoshop). Second, if your computer is equipped with Adobe Acrobat (full program, not just the Reader), you can use the 'Print' command to export to a digital PDF file (select 'Adobe PDF' as your printer). Once the file has been exported to PDF, you can open, print, edit or copy/paste as you would any PDF file.