GENERAL Q1: What topics have been covered in the lecture on traffic dynamics and simulation? A1: data, models, applications (elaborate) Q2: What are the main measuring methods to obtain traffic data? A2: stationary detector cross-sections (e.g., single/double induction loops), video, floating cars, mobile phones Q3: Please list the main categories/types of traffic flow data. What typical quantities of traffic flow are measured by each category? A3: (i) Cross-section data: (i1): Single vehicle: Individual passage times, velocities, and lengths/occupancy times (i2): Aggregated: Average velocity, flow, occupancy, truck percentage (ii) FCD: travelling time through a section, velocity profile, location profile for a few vehicles (iii) Trajectory data: A complete set of trajectories {x_i(t), lane_i(t)} for all vehicles in a given spatiotemporal region (iv) Floating-phone data: approximate location from active cellular phones Q4: (I draw a trajectory diagram with a jam) How to determine density, flow, velocity, and travelling time? What about the lines ending/beginning in the middle of the diagram? A4: Q5: What data capturing methods can be used to measure traffic flow: (i) Single-loop detectors, (ii) double loop detectors, (iii) FCD, (iv) FPD, (v) trajectory data? A5: (i),(ii), (v) Q6: What data capturing methods can be used to measure local velocity? A6: (i), (iii), (v) Q7: What data capturing methods can be used to measure traveling times? A7: (iii), (iv), (v) Q8: Please state what is meant by data fusion in the traffic context A8: Merge different data categories in a consistent way thereby resolving problems due to contradicting traffic data channels and different data types MODELS Q9: What are the main types of models used for modeling traffic flow? A9: Micromodels (including CA), and macromodels Q9a: What are the main differences of pedestrian and vehicular traffic? A9a: Dimensionality, 2D vs. 1D Q10: What are typical dynamical variables in each model class? A10: Micro: x_i(t), v_i(t), lane_i(t)[veh], y_i(t)[ped] for each vehicle/pedestrian/moving agent Macro: Density rho(x,t), vel V(x,t), flow Q(x,t), possibly disaggregated for different lanes and vehicle classes; flow density for pedestrian traffic Q11: What are the main distinctions of the traffic models with respect to the mathematical form? Please give an example for each mathematical category, micro or macro? PDE, ODE, coupled maps, CA A11: PDE: d/dt rho(x,t)+d/dx Q(x,t)=0 ODE: dx_i/dt=v_i, dv_i/dt=a_i(s_i,v_i,Delta v_i) CM: v(t+Delta t)=v(t)+a(s(t), v(t), Delta v(t)) Delta t, s(t+Delta t)=s+v Delta t+1/2a 9Delta t)^2 CA: Iterated map of occupance of cells in {0,1}^n, and discrete velocities of occupied cells Q12: Which model type is better suited for applications (i) traffic-state recognition and short-term forecast, (ii) simulate influence of ACC vehicles in traffic A12: (i) Macro, (ii) Micro Q13: Please derive the continuity equation for vehicular traffic on a homogeneous road from vehicle conservation/inflow-outflow balance A13: dn/dt=dx*d/dt rho=Qin-Qout=Q(x)-Q(x+dx)=-dx*d/dx Q => d/dt rho+d/dx Q=0; Q=rho*V Q14: Pleqase generalize the continuity equation to include onramps and offramps A14: Addtl. term (dn/dt)_rmp=Qrmp*dx/L => rhs term Qrmp/L (Qrmp<0 for offramps) A15a: LWR model Q15: Please draw a fundamental diagram for traffic flow A15: (Skizze) Q16: (Punkt auf gestauter Seite) Please show graphically how to determine the velocity of vehicles, and propagation velocity of small perturbations for traffic characterized by this point. A16 (Ursprungsgerade, Tangente) Q16a: What is the road capacity in the LWR models? Q17: The propagation velocity: Does it relate to a stationary or moving reference frame? Q18: (weiterer Punkt auf der freien Seite) How to determine the propagation velocity of jam fronts: Transition free-congested, congested/free Q19: Queu behind red traffic light and its dissolution: Draw a spatiotemporal diagram of density and draw some Trajectories into it Q20: Drawbacks of first-order models? A20: No growing jams, no hysteresis/metastability, no wide scattering Q21: General form of macroscopic models with dynamic velocities? Write it in a form such that the microscopic vehicle acceleration can be seen (acceleration field A(x,t)) A21: dV/dt=(d/dt+v d/dx)V=A(x,t) Q22: (The trajectory diagram from the data section, dissolution fromt of jams) What is the sign of ablpart{V}{t} and \abltot{V}{t}? A22: >0, <0 Q23: Please define metastability, linear instability, and convective instability in the traffic context. At which density ranges these instabilities typically show up? How does one derive linear instability? Q24: Micromodels: What are typical model parameters? Which human factors can be modelled? APPLICATIONS Q25: Describe some applications of traffic flow simulations A26: Traffic-state detection by stationary detectors or floating cars (car navigation); (1) traffic state forecast (e.g., by the shockwave dynamics of the upstream fronts of LWR models) (2) Generating the traffic background in research (traffic psychology) and game driving simulators (3) Learning/determining which driver's behaviour is safe, stable, and efficient, and which is not (microscopic model parameters) (4) Determining traffic related effects (safety,stability, efficiency) of all the new vehicle innovations such as ACC, navigation, traffic-light assistants, autonomous driving