Table 3.
Systematic impact of ADAS on traffic flow operation.
| Study | System analyzed | Behavior considered |
Traffic flow models | System impact |
|---|---|---|---|---|
| Lundgren and Tapani (2006) | ADAS (no function specified) | PRT (0–1.5 s) and desired headway (1–3 s) |
Gazis-Herman-Rothery (GHR) model for car-following (CF) behavior | 130% increase of time-exposed time-to-collision (TET) and 280% increase of time-integrated TTC (TIT) as PRT increases from 0 to 1.5 s; 233% decrease of TET and 300% decrease of TIT as desired headway increases from 1 to 3 s |
| Van Arem et al. (2006) | CACC | NA | The MIXIC model for CF and lane-changing (LC) behavior | Reduction in number of shockwaves and increase in average speed as CACC penetration rates increases. Reduction in traffic safety because CACC vehicle platoons prevent other vehicles from merging. No significant impact on throughput |
| Hegeman et al. (2009) | Overtaking assistant system (OAS) | Driver’s overtaking frequency | The rural traffic simulator (RuTSim) | The impact of OAS penetration rate was not significant. The 11 s minimum overtaking time threshold was found to minimize the safety measures such as minimum time-to-collision (TTC), TET and TIT |
| Schakel et al. (2010) | CACC and acceleration advice controller (ACC) | Driver’s acceleration affected by ACC | Intelligent Driver Model (IDM) for CF behavior | Traffic stability is analyzed for a single lane road with 2000 veh/h traffic load. The non-CV case has growing shockwave duration and range. The AAC and CACC cases have decreased shockwave duration and increase shockwave range and speed |
| Kesting et al. (2010) | Adaptive cruise control (ACC). | NA | IDM and constant-acceleration heuristic | 0.3% increase of maximum flow rate due to 1% increase of ACC penetration rate |
| Wang et al. (2014) | Ecological adaptive cruise control (EcoACC) | NA | The EcoACC control inputs determined based on model predictive control | With EcoACC, 17% reduction in flow and vehicle mile traveled (VMT) and 19.5% reduction in average CO2 emission under low density traffic (20 veh/km); 31.3% increase in flow and VMT and 9% reduction in average CO2 emission under high density traffic (40 veh/km) |
| Khondaker and Kattan (2015) | Variable Speed Limit (VSL) under the CV environment | Desired speed | IDM for CF behavior | 20% reduction of total travel time, 6–11% of safety improvement, and 5–16% reduction in fuel consumption |