A before-after impact assessment of COVID-19 outbreak on bike-sharing ridership in Washington, DC

Figures & data

Table 1. Descriptive statistics of CaBi variables by quarter of the 2019 and 2020 years

Description	Quarter
	Q1	Q2	Q3	Q4
# of stations
Stations (2019|2020)	378|311	380|318	385|332	391|341
Ratio (2020/2019)	0.83	0.84	0.86	0.87
# of daily trips
Total 2019	393,991	791,992	894,903	776,536
Total 2020	452,551	304,664	562,698	552,938
Minimum (2019|2020)	540|1,175	1,727|622	5,206|2,437	1,310|1,838
Maximum (2019|2020)	7,839|7,763	15,715|8,243	11,474|12,596	11,707|12,380
Mean (2019|2020)	4,378|4,973	8,609|3,312	9,727| 6,116	8,533|6,076
Median (2019|2020)	4,500|5,041	9,254|2,754	10,109|5,876	9,272|6,062
Std. Dev. (2019|2020)	1,694|1,445	2,623|1,937	1,230|1,650	2,293|2,056
Ratio Total (2020/2019)	1.15	0.38	0.63	0.71
Average daily travel time (min)
Minimum (2019|2020)	1|1	1|1	1|1	1|1
Maximum (2019|2020)	120|120	120|120	120|120	120|120
Mean (2019|2020)	13|13	17|20	17|21	15|19
Median (2019|2020)	10|10	12|15	12|15	11|13
Std. Dev. (2019|2020)	12|11	16|19	16|19	13|18
Ratio mean (2020/2019)	1.00	1.18	1.24	1.06

Note: Q1 = Winter; Q2 = Spring; Q3 = Summer; Q4 = Fall; Std. Dev. = Standard Deviation.

Table 2. Descriptive statistics of COVID-19 variables by quarter of the 2020 year

Description	Quarter
	Q1	Q2	Q3	Q4
# of daily COVID-19 cases (2020)
Total COVID-19 cases	0	8,271	5,192	7,636
Minimum	0	0	12	14
Maximum	0	335	234	371
Mean	0	91	56	84
Median	0	99	56	66
Std. Dev.	0	77	28	59
# of daily COVID-19 patients (2020)
Total COVID-19 patients	0	21,666	11,428	9,152
Minimum	0	0	69	73
Maximum	0	477	295	160
Mean	0	236	124	101
Median	0	304	94	95
Std. Dev.	0	181	61	19

Note: Q1 = Winter; Q2 = Spring; Q3 = Summer; Q4 = Fall; Std. Dev. = Standard Deviation.

Figure 1. Daily CaBi trips and COVID-19 cases and patients.

Table 3. Descriptive statistics of the population profile

Variable	Minimum	Maximum	Mean	Median	Std. Dev.
Area	2.54	11.94	8.56	8.91	2.79
Males	33,916.00	41,368.00	38,334.25	38,953.00	2424.44
Females	38,431.00	46,001.00	42,601.25	43,037.00	2538.91
Households	29,266.00	40,100.00	34,173.75	33,281.50	4226.51
Income	17,596.00	83,452.00	47,377.25	45,931.00	21,702.79
Work	30,771.00	63,951.00	46,730.50	47,586.00	10,395.95
CarTruck	1046.00	3393.00	2433.00	2410.00	667.46
Public	11,025.00	24,145.00	16,214.13	15,656.50	4658.81
Walk	597.00	20,663.00	6247.00	3417.00	6538.40
Others	442.00	5753.00	3079.13	2826.50	1835.11

Note: Area = Ward area in square miles; Males = Male population; Females = Female population; Households = # of households; Income = Per capita income in dollars; Work = Population of +16 years old who commute to work; CarTruck = Population of +16 years old who commute to work using cars, trucks, or vans; Public = Population of +16 years old who commute to work using public transportation excluding taxicabs; Walk = Population +16 years old who walk to commute to work; Others = Population of +16 years old who use other means to commute to work; Std. Dev. = Standard deviation.

Table 4. Correlations between CaBi variables and the population profile (demographics, socio-economics, and transportation)

2019 Q2 (Members|Casual users)
	Stations	Trips	Time	Area	Males	Females	Households	Income	Work	CarTruck	Public	Walk	Others
Stations	1|1	1*|0.9*	−0.5|0.4	−0.6|-0.6	0.7|0.7	−0.4|-0.4	0.8*|0.8*	0.6|0.6	0.8*|0.8*	−0.6|-0.6	0.4|0.4	0.9*|0.9*	0.8*|0.8*
Trips	1*|0.9*	1|1	−0.5|0.5	−0.6|-0.3	0.6|0.4	−0.4|-0.4	0.8*|0.8*	0.6|0.7	0.8*|0.6	−0.6|-0.7*	0.4|0.1	1*|1*	0.8*|0.6
Time	−0.5|0.4	−0.5|0.5	1|1	0.7|0.2	−0.6|0.2	0.6|0.5	−0.1|0.6	0|0.6	−0.5|0.3	0.1|-0.3	−0.5|0	−0.3|0.4	−0.6|0.1
2019 Q3 (Members|Casual users)
Stations	1|1	1*|0.9*	−0.3|0.4	−0.6|-0.6	0.7|0.7	−0.4|-0.4	0.8*|0.8*	0.6|0.6	0.8*|0.8*	−0.6|-0.6	0.4|0.4	0.9*|0.9*	0.8*|0.8*
Trips	1*|0.9*	1|1	−0.3|0.6	−0.5|-0.3	0.6|0.5	−0.4|-0.4	0.8*|0.8*	0.6|0.7	0.8*|0.6	−0.6|-0.7	0.4|0.2	1*|1*	0.8*|0.6
Time	−0.3|0.4	−0.3|0.6	1|1	0.6|0.2	−0.5|0.1	0.5|0.3	0.1|0.7	0.2|0.6	−0.4|0.3	−0.1|-0.4	−0.5|0	−0.1|0,5	−0.5|0.1
2019 Q4 (Members|Casual users)
Stations	1|1	1*|0.9*	−0.4|0.5	−0.6|-0.6	0.7|0.7	−0.4|-0.4	0.8*|0.8*	0.6|0.6	0.8*|0.8*	−0.6|-0.6	0.4|0.4	0.9*|0.9*	0.8*|0.8*
Trips	1*|0.9*	1|1	−0.3|0.7	−0.5|-0.3	0.6|0.5	−0.4|-0.4	0.8*|0.8*	0.6|0.7	0.8*|0.6	−0.6|-0.7	0.4|0.2	1*|1*	0.8*|0.6
Time	−0.4|0.5	−0.3|0.7	1.0|1	0.7|0	−0.6|0.3	0.5|0.2	0.1|0.9*	0.2|0.9*	−0.5|0.5	0|-0.3	−0.5|0.1	−0.2|0.6	−0.6|0.3

Note: Q1 = Winter; Q2 = Spring; Q3 = Summer; Q4 = Fall; Area = Ward area in square miles; Males = Male population; Females = Female population; Households = # of households; Income = Per capita income in dollars; Work = Population of +16 years old who commute to work; CarTruck = Population of +16 years old who commute to work using cars, trucks, or vans; Public = Population of +16 years old who commute to work using public transportation excluding taxicabs; Walk = Population of +16 years old who walk to commute to work; Others = Population of +16 years old who use other means to commute to work.; * indicates that values are significant at the 95% confidence level or higher (2-tailed).

Figure 2. Correlations between COVID-19 cases, CaBi variables and population profile (demographics and socio-economics) in 2020.

Note: Area = Ward area in square miles; Males = male population; Females = female population; Households = # of households; Income = per capita income in dollars; Stations = # of stations; Trips = # of trips; Time = average travel time; Cases = # of COVID-19 cases; Framed values are significant at the 95% confidence level (2-tailed) or higher.

Figure 3. Correlations betweenCOVID-19 cases, CaBi variables and population profile (demographics and transportation) in 2020.

Note: Work = population of +16 years old who commute to work; CarTruck = population of +16 years old who commute to work using cars, trucks, or vans; Public = population of +16 years old who commute to work using public transportation excluding taxicabs; Walk = population of +16 years old who walk to commute to work; Others = population of +16 years old who use other means to commute to work; Framed values are significant at the 95% confidence level (2-tailed) or higher.

Figure 4. Density map of the 2019-to-2020 change in average daily trip generation.

Table 5. MENB Models for ridership of CaBi members

Model			MENB 1		MENB 2		MENB 3		MENB 4
Fixed-effects statistics			Estimate	p-value	Estimate	p-value	Estimate	p-value	Estimate	p-value
Fixed-effects variables	Intercept		2.6530	<0.01	2.1140	0.02	1.6993	<0.01	2.4344	<0.01
	Weekday		−0.0182	0.35	−0.1007	<0.01	−0.0015	0.94	−0.0026	0.9
	Time		0.0188	0.73	−0.0203	<0.01	0.0059	0.91	0.0071	0.9
	Stations		0.0194	<0.01	0.0202	<0.01	0.02041	<0.01	0.0201	<0.01
	Cases		−0.0013	0.5	−0.0002	0.67	−0.0002	0.17	0.0001	0.92
	Order		−1.5872	<0.01	0.394	<0.01	−0.1609	0.042	−0.2852	0.44
	Lift		0.9939	<0.01	0.2696	<0.01	0.7657	<0.01	−0.4943	0.38
Random-effects statistics (10^−3)			Variance	Std. Dev.	Variance	Std. Dev.	Variance	Std. Dev.	Variance	Std. Dev.
Random-effects variables	Season	Intercept	0.06 10^2	0.75 10^2	0.01 10^2	11.45 10^2	0.91 10^2	301.61	0.85 10^2	2.91 10^2
		Time	7.58 10^−2	0.09 10^2			1.41 10^−1	11.86	1.79 10^−1	0.13 10^2
		Stations			1.58 10^−2	0.04 10^2	1.76 10^−3	1.33	1.39 10^−3	0.12 10^2
		Cases	7.71 10^−6	8.78 10^−2	3.92 10^−4	6.26 10^−1			2.37 10^−6	4.87 10^−2
	Order	Intercept	1.56 10^−3	0.01 10^2	1.97 10^−6	4.43 10^−2	1.74 10^−1	13.18	8.08 10^−1	0.28 10^2
		Time	0.03 10^2	0.51 10^2			0.05 10^2	71.14	0.04 10^2	0.66 10^2
		Stations			2.43 10^−7	1.56 10^−2	9.03 10^−3	3.01	7.87 10^−3	0.03 10^2
		Cases	2.54 10^−3	0.02 10^2	1.04 10^−6	3.23 10^−2			2.26 10^−5	1.50 10^−1
	Lift	Intercept	4.40 10^−3	0.02 10^2	4.79 10^−2	0.07 10^2	6.16 10^2	784.67	3.25 10^−2	0.06 10^2
		Time	0.01 10^2	0.35 10^2			5.63 10^−1	23.73	8.06 10^−1	0.28 10^2
		Stations			6.22 10^−7	2.49 10^−2	1.20 10^−2	3.46	1.20 10^−2	0.03 10^2
		Cases	1.59 10^−3	1.26	7.75 10^−7	2.78 10^−2			2.28 10^−2	4.77 10^−1
Overdispersion parameter			1.011		1.033		0.999		0.982
Akaike Information criterion (AIC)			5500.8		5589.5		5484.5		5512.2
Bayesian Information criterium (BIC)			5602.3		5691.0		5586.0		5660.5

Note: Weekday = Dummy variable (1 for weekdays and 0 for weekend days); Time = Average travel time between pickup and drop-off station; Stations = # of pickup

stations; Cases = # of daily COVID-19 cases; Season = 2020 seasons (Q1: Winter, Q2: Spring, Q3: Summer, and Q4: Fall); Order = Dummy variable for the stay-at-

home order (0 and 1 respectively for the period before and after April 1); lift = Dummy variable for the stay-at-home lift (0 and 1 respectively for the period before and after

May 29).

Table 6. MENB models for ridership of CaBi casual users

Model			MENB 1		MENB 2		MENB 3		MENB 4
Fixed-effects statistics			Estimate	p-value	Estimate	p-value	Estimate	p-value	Estimate	p-value
Fixed-effects variables	Intercept		3.5430	<0.01	2.6409	<0.01	2.7734	<0.01	3.4306	<0.01
	Weekday		−0.1280	<0.01	−0.1691	<0.01	−0.1174	<0.01	−0.0970	<0.01
	Time		0.0404	0.92	0.0277	<0.01	0.0200	0.72	0.0326	0.90
	Stations		0.0152	<0.01	0.0171	<0.01	0.0185	0.02	0.0145	0.96
	Cases		0.0054	1	−0.0007	0.40	−0.0002	0.51	0.0065	0.99
	Order		−1.5105	0.02	−0.0447	0.80	−0.9212	<0.01	−1.3498	<0.01
	Lift		0.5707	0.55	0.0684	0.53	0.7627	0.01	−0.3580	0.74
Random-effects statistics (10^−3)			Variance	Std. Dev.	Variance	Std. Dev.	Variance	Std. Dev.	Variance	Std. Dev.
Random-effects variables	Season	Intercept	6.00 10^2	774.65	2.73 10^2	522.23	7.11 10^2	843.00	2066.00	1437.27
		Time	7.88 10^−1	28.07			2.97 10^−2	54.52	68.37	261.48
		Stations			3.22 10^−3	1.79	6.68 10^−2	8.17	0.73	27.06
		Cases	2.42 10^−3	1.56	3.33 10^−4	0.58			0.09	9.48
	Order	Intercept	2.75 10^2	524.72	0.00	0.00	2.05 10^−7	0.01	19.10	138.19
		Time	2.04 10^2	451.13			5.37 10^−1	23.17	1.60	40.04
		Stations			1.68 10^−3	1.29	9.26 10^−3	3.04	94.83	307.95
		Cases	4.76 10^2	690.25	7.20 10^−4	0.85			503.60	709.63
	Lift	Intercept	3.94 10^2	627.53	1.61 10^2	401.16	2.81 10^2	530.50	176.00	419.58
		Time	1.26 10^2	354.33			238.00 10^−2	48.80	100.20	316.47
		Stations			3.97 10^−3	1.99	1.99 10^−2	4.46	119.70	345.92
		Cases	2.63 10^2	513.10	5.25 10^−5	0.23			3.58	59.86
Overdispersion parameter			0.992		1.012		0.999		0.998
Akaike Information criterion (AIC)			4982.1		5008.4		4935.5		5019.8
Bayesian Information criterium (BIC)			5083.6		5109.9		5037.0		5168.1

Note: Weekday = Dummy variable (1 for weekdays and 0 for weekend days); Time = Average travel time between pickup and drop-off station; Stations = # of pickup

stations; Cases = # of daily COVID-19 cases; Season = 2020 seasons (Q1: Winter, Q2: Spring, Q3: Summer, and Q4: Fall); Order = Dummy variable for the stay-at-

home order (0 and 1 respectively for the period before and after April 1); lift = Dummy variable for the stay-at-home lift (0 and 1 respectively for the period before and after

May 29).

Figure 5. MENB 3 diagnostics on the seasonal effects for CaBi members (left) and casual users (right).