Traffic and environmental impacts of constructing and operating a BRT service: Case study in Amman, Jordan

Figures & data

Figure 1. Amman BRT routes (GAM, 2021).

Figure 2. Study methodology flow chart.

Figure 3. Yajouz intersection general layout on BRT line 1.

Table 1. Number of lanes by stage and traffic streams

Traffic Stream	Before	During	After Completion
East Bound Left Turn (EBLT)	3	3	2
East Bound Through EBTH	4	3	3
East Bound Left and U Turn (EBLT/UT)	1	Prohibited	1
West Bound U Turn (WBUT)	2	1	1
West Bound Through (WBTH)	4	4	3
West Bound (WBRT)	2	2	2
South Bound Left Turn (SBLT)	3	2	3
South Bound Left and U Turn (SBLT/UT)	1	U-Turn was Prohibited	1
South Bound Right Turn (SBRT)	2	2	2

Figure 4. Intersection layout before, during and after construction.

Figure 5. Test segments for the travel time and speed study.

Table 2. Description of air quality index levels

AQI	Air Pollution Level	Health Implications
0–50	Good	Air quality is considered satisfactory, and air pollution poses little or no risk
51–100	Moderate	Air quality is acceptable; however, for some pollutants there may be a moderate health concern for a very small number of people who are unusually sensitive to air pollution.
101–150	Unhealthy for Sensitive Groups	Members of sensitive groups may experience health effects. The general public is not likely to be affected.
151–200	Unhealthy	Everyone may begin to experience health effects; members of sensitive groups may experience more serious health effects
201–300	Very Unhealthy	Health warnings of emergency conditions. The entire population is more likely to be affected.
300+	Hazardous	Health alert: everyone may experience more serious health effects

Table 3. The average control delay as a measure of the effectiveness of signalized intersections

Level of Service	Average Control Delay (sec/veh)	General Description
A	≤10	Free Flow
B	>10–20	Stable Flow (slight delays)
C	>20–35	Stable Flow (acceptable delays)
D	>35–55	Approaching unstable flow(tolerable delay, occasionally wait through more than one signal cycle before proceeding)
E	>55–80	Unstable flow (intolerable delay)
F	>80	Forced Flow (Jammed

Table

ANOVA test	Passenger Car	Taxi	Large Bus	Small Bus	Truck
F-Value	0.013	0.590	0.814	1.234	0.742
p-value	0.99	0.898	0.8462	0.7448	0.8633

Figure 6. Intersection total entry volume at by construction stage.

Figure 7. Traffic mix distribution by traffic movement and stage of construction (%).

Table

Vehicle Type	Private Passenger Car		Taxi		Large Bus		Small Bus		Truck
Statistics	F	Sig.	F	Sig.	F	Sig.	F	Sig.	F	Sig.
Phase	12.421	0.000	5.770	0.004	3.268	0.038	11.695	0.000	9.178	0.000
Stream	0.681	0.703	1.346	0.278	2.282	0.064	0.632	0.741	0.577	0.785

Table 4. Change in public transport ridership over time: peak hourly pax

Stage of Construction or Operation scenario	Survey Date	Buses		Passengers		Total
		EB	WB	EB	WB
Before	October, 2015	65	83	1,105	1,411	2,516
During	October, 2016	60	78	1,020	1,326	2,346
After: No BRT	October, 2017	67	82	1,139	1,394	2,533
After: With BRT	November,2022	83	82	1,411	1,394	2,805

Table 5. Traffic flow parameters’ variation by stage and related statistical analysis

Traffic Parameter	Contraction Stage	Mean	Std. Deviation	ANOVA Test	T-test (Compare two independent means)
					Before- During	Before- After	Before-BRT	During - After	During - BRT	After- BRT
Peak Hour Factor	Before	0.861	0.033	F = 2.153 P = 0.144	t = −1.271 p = 0.226	t = −2.543, p = 0.023	t = 1.126, p = 0.275	t = −0.496, p = 0.63	t = 0.165, p = 0.871	t = 0.718, p = 0.483
	During	0.896	0.073
	After	0.912	0.048
	BRT	0.890	0.071
Operating Speed km/h	Before	15.75	3.357	F = 2.306 P = 0.108	t = −0.899 p = 0.205	t = −4.335, p = 0.004	t = −2.70, p = 0.021	t = −3.13, p = 0.013	t = −2.30, p = 0.035	t = 1.903, p = 0.058
	During	17.33	6.82
	After	22.67	4.27
	BRT	20.73	5.21
Travel Time Delay	Before	118.3	234	F = 0.19 P = 0.83	t = 0.602 p = 0.549	t = 0.07. p = 0.945	t = 0.065, p = 0.949	t = −0.569 p = 0.573	t = 0.603, p = 0.551	t = 0.022, p = 0.983
	During	91.04	84
	After	111.5	54.8
	BRT	112.5	57.2

Table 6. Traffic streams’ delay variation by stage and related statistical analysis

Stream	Stage	Statistical Parameter		LOS	ANOVA Test
		Mean Sec/veh	Std. Deviation		F/T-Test	Sig.
EBLT	Before	158	46.57	F	2.35	0.078
	During	79	34.87	E
EBTH	Before	72	26.16	E	3.358	0.044
	During	73	42.10	F
	After	51	32.53	D
	BRT	20.7	19.40	C
EBUT	Before	96	31.82	F	NA
NBTH	Before	122	75.19	F
SBLT	Before	78	41.74	E	0.49	0.694
	During	76	13.13	E
	After	95	410	F
	BRT	99	41.0	F
SBRT	Before	99	92.9	F	0.58	0.6425
	During	26	109.2	C
	After	91.7	108.0	F
	BRT	61.0	5.83	E
WBTH	Before	114	31.38	F	0.763	0.531
	During	65	63.54	E
	After	99	69.21	F
	BRT	109	48.5	F
WBUT	Before	89	26.16	F	17.8	0.003
	After	32		C
	BRT	36	11.6	D

NA: Not Applicable: No enough Observation

Figure 8. Jordan University Street station: Air quality index, location, daily variation, and monthly variation pattern from 2019 to 2022.

Table 7. Simulated one hour run and the total traffic entry - before construction stage- as measure of effectiveness results

Run	1	2	3	4	5	6	7	8	9	10	11	RMSPE
Simulated Volume	6,569	6,438	6,663	6,593	6,720	6,584	6,639	6,749	6,569	6,704	6,621	2.07%

Table

Stage	Average Delay (sec)	Simulated Delay (sec)	Difference (sec)	MAER
Before	100.9	121.9	21	20.82%
During	63.8	55.8	−8	−12.54%
After	65.0	67.8	2.75	4.23%
After BRT	53.74	42.5	−11.05	−13.8%
All Stages	73.99	76.93	3.98	−0.35%

Figure 9. Observed vs simulated delay as MOE validation results.

Table 8. The field delay vs modelled delay by stage and traffic streams

Stream	Stage	Field Delay Time		Modelled control Delay
		Delay (sec)	LOS	Delay(sec)	LOS
EBLT	Before	158	F	157	F
	During	79	E	93	F
EBTH	Before	72	E	63	E
	During	73	E	31	C
	After	51	D	29	C
	BRT	20.7	C	27.5	C
EBUT	Before	96	F	110	F
SBLT	Before	78	E	157	F
	During	76	E	83	F
	After	95	F	69	E
	BRT	99	F	76	E
SBRT	Before	99	F	120	F
	During	26	C	16	B
	After	91.7	F	113	F
	BRT	61	E	47	D
WBTH	Before	114	F	175	F
	During	65	E	56	E
	After	99	F	33.9	C
	BRT	62	E	36	D
WBUT	Before	89	F	71	E
	After	32	C	23	C
	BRT	36	D	152	F
Average (sec/veh)		76.02		79.02
Standard Deviation (sec/veh)		31.8		49.35
Pearson Correlation Coefficient		r = 0.585, p = 0.004

Table

Standard Deviation	Approach	85.67	26.60	21.36	12.49	7.01	32.60
	Control	43.8	32.8	37.7	50.5	16.86	23.50

Figure 10. Average modelled delays at the intersections with the study area by stage.

Figure 11. Average modelled traffic stream delays and queue length by stage.

Figure 12. Simulated total and denied delay by stage of construction/operation scenario: sixty-minute simulation.

Table

Standard Deviation	Speed	1.9	12.8	11.3	13.3	11.6	13.1
	Density		5.3	21.1	52.9	40.4	41.3

Figure 13. Simulated average speed and Street density by stage of construction/operation scenario.

Table

Standard Deviation	Stops	0.18	0.40	0.42	0.39	0.35	0.38	Stop/veh (No.)
	Efficiency	1.5	5.6	4.2	5.1	4.7	4.8
	Used	5.6	203	257	289	242	180

Figure 14. Simulated fuel consumption and stops per vehicle by stage of construction/operation scenario.

Table

Standard Deviation (g)	HC	4	854	571	804	650	509
	CO	162	15,408	13,180	15,406	12,954	10,340
	NOX	16	1,293	1,131	1,268	1,167	1,001

Figure 15. Simulated pollutant emission by stage of construction/operation scenario.

Table 9. Travel time pattern by type and route selection and associated statistical tests

	Group	Parameter	Mean	N	Std. Deviation	t-value	sig
Traveller Type	Students	Travel time during Construction (min)	56.17	12	28.33	5.83	0.00
		Original travel time origin (min)	27.50	12	16.58
	non-Students	Travel time during Construction (min)	45.53	38	21.07	4.49	0.00
		Original travel time origin (min)	28.66	38	17.05
Route Selection	Take Alternative Route	Travel time during Construction (min)	43.04	26	16.78	6.08	.000
		Original travel time origin (min)	23.46	26	14.34
	Remain on the Route	Travel time during Construction (min)	53.54	24	27.88	3.52	.002
		Original travel time origin (min)	33.71	24	17.87
	All	Travel time during Construction (min)	48.08	50	23.16	6.26	.000
		Original travel time origin (min)	28.38	50	16.78

Table

t-value	4.36	4.58	4.61	2.35
p	0.005	0.01	0.00	0.031

Figure 16. Breakdown of the travel time pattern by traveller type and route selection and associated statistical tests.

Figure 17. A render of Yajouz intersection upon completion of and BRT operation started.

GAM. (2021) The bus rapid transit (BRT) project. http://www.ammanbrt.jo/

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Data availability statement

Some or all data, models, or code that support the findings of this study are available from the corresponding author upon reasonable request.