Segment Information (Details) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2019 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2018 USD ($)
Segment Reporting Information [Line Items]
Number of Reportable Segments			2
Revenue	$ 4,225	$ 3,893	$ 7,597	$ 6,903
Gross profit	3,026	3,192	5,621	5,755
Amortization of intangible assets	149	120	299	231
Intangible assets	3,780	3,356	3,780	3,356
Intersection [Member]
Segment Reporting Information [Line Items]
Revenue	2,512	2,842	4,584	5,259
Gross profit	2,239	2,596	4,031	4,782
Amortization of intangible assets	91	92	183	184
Intangible assets	1,926	2,293	1,926	2,293
Highway [Member]
Segment Reporting Information [Line Items]
Revenue	1,713	1,051	3,013	1,644
Gross profit	787	596	1,590	973
Amortization of intangible assets	58	28	116	47
Intangible assets	$ 1,854	$ 1,063	$ 1,854	$ 1,063

The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

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