# Study on Quantitative Expression of Cycling Workload
## 3 Methods and Materials
### Field Cycling Experiment Scheme Design  
As stated in previous sections, there are many variable bikeway characteristics that can be categorized as geometric elements (cycling width, curve radius, and longitudinal gradient, etc.) and facility design (e.g., separation type--barrier, pavement marking, and curb); these impact cyclists' safety and comfort and reflect cycling workload. In addition, cycling speed has a specific influence due to the necessary physical effort. Hence, in order to measure cycling workload and to obtain threshold values, it is important to control different stress and comfort conditions for cyclists, which can be realized by arranging different combinations of typical bikeway characteristics such as narrow and wide cycling widths with different speeds.  
So, we designed a field cycling experiment to be carried out in a variety of conditions on a straight section of a bike path--such as varying the roadway edge, cycling speeds, directions, and widths (see Figures 2-4, respectively)--to simulate scenarios that led to changes in cycling workload. It was decided that the test road should be free of motor vehicles and e-bikes in order to accurately reflect the circumstances of a true exclusive bicycle path where a cyclist's behavior was the only variable; here, their own requirements were the only consideration for the road users while ensuring the safety of the participants. Therefore, the site for the test road was selected on a university campus with asphalt concrete and flat pavement--these were selected to avoid any unpleasant feelings that might be caused by pavement materials or surface. The test road segment was 280 m long, with an additional 70 m long pretest road for cyclists' adaptability. Moreover, various widths of the test road were established and organized as shown in Figure 2, in accordance with the minimum width specifications of various international standards (Table 3). Figure 3 illustrates a variety of road edge scenarios, including curb + barrier and curb + marking scenarios. Figure 4 depicts the cycling direction conditions, including single-file, one-way abreast cycling, and two-way cycling. The tested cycling speeds for all these road scenarios were in the range of 10-25 km per hour. The final settings of test road scenarios are presented in Table 4.  
Figure 2: Cycling workload scenarios—different widths.  
Figure 4: Different route scenarios: (**a**) single-file; (**b**) one-way abreast cycling; (**c**) two-way cycling.  
Figure 3: Cycling workload scenarios—different road edges. (**a**) Curb + marking scenario; (**b**) curb + barrier scenario.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Country/Region** &
\begin{tabular}{c} **Minimum** \\ **Width (m)** \\ \end{tabular} & **Scenarios** \\ \hline Netherlands (CROW, 2017) [8] & 1.0 & Consider clearance between cyclists \\ U.S.A (AASHTO, 2012) [9] & 1.2 & Minimum operating for single cyclist \\ UK (TSO, 2020) [10] & 1.0 & Bicycle width and wobble width \\ Australia (Austroads, 2017) [11] & 1.0 & Minimum path width \\ China, mainland ([PERSON], 2016) [12] & 1.0 & Bicycle width and wobble width \\ China, Taiwan (PD, 2017) [13] & 0.80 & Minimum path width \\ Ireland (NTA, 2011) [14] & 0.75 & Minimum single-file regime \\ \hline \hline \end{tabular}
\end{table}
Table 3: Basic cycling widths in the guidelines of various countries or regions.