The research presented in this paper characterizes driver stopping behavior at the onset of a yellow phase on high-speed signalized-intersection approaches through the use of controlled field data gathered from 60 test subjects by means of an in-vehicle differential global positioning system. A total of 745 data records were available for analysis of all drivers who stopped at the onset of the yellow phase. These ranged from a minimum time to the stop bar (TTS) of 1.34 s to a maximum of 6.19 s. Statistical analyses were used to investigate the effects of the TTS bar, grade (uphill and downhill), age (younger than 40 years old, 40 to 59 years old, and 60 years of age or older), and gender on seven dependent measures of driver performance, including perception time, reaction time, perception-reaction time, braking time, stopping time, and stopping accuracy. The study demonstrated that driver perception time was not affected by TTS, while reaction time was dependent on TTS, roadway grade, and driver age. Younger drivers had longer reaction times than the older group, but they were able to stop over a shorter period of time, as they typically applied more aggressive braking rates. A lower perception-reaction time was found for drivers who had their foot lifted off the accelerator at the onset of the yellow phase. Male drivers showed slightly higher braking times than female drivers, with no significant differences between male and female drivers. Furthermore, the results demonstrated that drivers who tried to stop in short TTSs were more likely to stop downstream of the stop line and that older drivers were significantly more accurate when they stopped than other age groups.

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Purpose: The diagnostic efficacy of fine needle aspiration cytology (FNAC) was evaluated to assess its value in accurate preoperative diagnosis of salivary gland lesions and to compare it to that of histopathologic diagnosis with discussion of the possible diagnostic pitfalls.
Patients and methods: This is a retrospective study of 82 patients presented at NCI, Cairo University with salivary gland lesion which underwent preoperative FNAC diagnosis with subsequent excision and histopathologic assessment. Cytology results were classified as negative, positive, inconclusive for cancer, and inadequate. The definitive histopathologic report according to WHO Histological typing was the gold standard diagnosis against which FNAC was compared.
Results: Our study included 82 patients underwent preoperative FNAC of major salivary glands with subsequent surgical excision. Male to female ratio was 1.4: 1. The mean age was 49 years. Parotid gland was involved in (68.3%), submandibular in (28%), and submental gland in (3.7%). Forty cases (48.8%) were cytologically diagnosed as benign lesions, 26 (31.7%) were malignant, and 10 (12.2%) were inconclusive. Cytological findings were nondiagnostic in 6 (7.3%). The most common benign cytologic diagnosis was pleomorphic adenoma, 16 out of 40 cases (40%), while the most common malignant tumor was carcinoma, 22 out of 26 cases (84.6%). Cytologic diagnoses were compared with histopathologic one and were true-negative in 37 (92.5%), true-positive in 33 (91.6%), false-negative in 3 (8.3%) and false-positive in 3 (7.5%) cases regarding detection of malignant tumors. The rates of agreement of histopathologic type for benign and malignant tumors were 89.2%, and 91%, respectively.

Conclusion: FNAC is a valuable diagnostic tool in preoperative assessment of salivary gland masses as preoperative recognition of malignant tumors may help to prepare both the surgeon and patient for an appropriate surgical procedure. Multidirectional aspiration is preferred to avoid selective sampling. Re-aspiration of solid portion after cyst fluid aspiration is necessary to decrease the rate of inadequacy. Attention to subtle morphologic changes, pitfalls, and limitations may aid in arriving at the right diagnosis. Lastly but not least correlation of cytologic diagnoses with clinical and radiological data (triple approach) is the golden rule for management of salivary gland lesion before any radical surgery.